Taylor's bid to win an amazing eighth successive World Matchplay, and a 16th triumph in total in Blackpool, continued as he saw off Chisnall 16-8 with his most clinical display of this year's event so far.
Chisnall out-scored his rival with nine 180s to Taylor's six, but four key ton-plus checkouts helped the Stoke great pull clear in mid-game before he went on to seal the win.
Chisnall actually took the game's opening leg with a 13-darter against the throw - but it would prove to be the only time he led during the contest as Taylor levelled and then finished a 14-darter to move 2-1 up.
Chisnall levelled with another 13-darter, but Taylor found another gear to hit an 11-darter - where the players traded 180s - before breaking throw by taking out 130 for a 12-darter to lead 4-2.
Double nine gave Taylor the next before Chisnall traded 12-dart finishes with his rival, only for another 130 checkout to put the world number two 7-3 up.
The next two were shared before Taylor pulled clear with six straight legs, which saw him land a brace of 68 checkouts before finishing 161 and 100 to leave the St Helens man trailing 14-4.
Chisnall rallied to win four of the next five to keep his feint hopes alive, but Taylor was ruthless in sealing victory, scoring a 180 and a 177 in a 12-darter as double 16 secured his spot in the last four.
"I hit my finishes well tonight and I want to kick on now," said Taylor, who is now unbeaten in 38 games on the Winter Gardens stage since 2007.
"Dave makes you nervous and puts you under pressure from the very start. The only way to beat Dave is to try and match him when he hits the big scores, and he's a great player.
"I'm going up there to try my best in every game and it's not about winning a 16th title here or an eighth in a row, it's just about winning this tournament."
2007 World Matchplay winner Wade remains on course to reach his sixth final at the Winter Gardens following his 16-11 win over gutsy Mensur Suljovic, who hit back from a seven-leg deficit to cause the left-hander some nervous moments.
After Wade took out double ten to break in the opening leg, Suljovic hit the same bed to level before finishing 101 to lead 2-1.
Wade, though, levelled before moving back ahead with a 13-darter, and after the Austrian landed two 180s in taking leg six, finishes of 108 and 48 moved the left-hander into a 5-3 lead.
Suljovic posted double 18 to hit back, but Wade landed 180s as he took the next two and finished 64, 86, 74 and 104 in a run which took him out to a 12-5 advantage.
Suljovic, though, responded in a similarly clinical fashion as he took six of the next seven legs - including a 116 finish - to pull back to 13-11, but the Austrian crucially missed one dart to cut the gap to one leg.
Wade stepped in to finish 74, once again in two darts, to take a 14-11 lead and then hit his favoured tops in the next two to book his semi-final place.
"I'm happy to have walked off stage a winner but I couldn't get going enough and it didn't quite come together for me," said Wade. "I couldn't find that extra gear and I thought I was going to, especially when I went 10-5 up.
"He didn't lay down or make it easy and I knew that would be the case. When I went 10-5 up I probably should have done the job done a little bit quicker, but I did enough.
"I was never really worried about losing the game but I eased up. I thought it was going to be really close but I'm happy because I won."
Wade has been defeated in four Blackpool finals by Taylor, but overcame his great rival in the World Grand Prix and The Masters last autumn and is in confident mood ahead of their semi-final.
"I know he will play extraordinary darts so if I beat him I've got to play brilliantly and I think at the moment I've got the game to beat him when he's playing well," Wade added.
"It hasn't come out and we can all talk, but I know I'm good enough to beat him at the moment when he's playing well, and I'm in a better place than I've ever been."
Taylor added: "James was brilliant tonight and he held his nerve and did the business. I'll be giving it everything and I'll fight him to the death.
"I think everybody's in for a treat because it's going to be two cracking semi-finals."
Saturday's other semi-final will see world number one Michael van Gerwen - last year's beaten finalist in Blackpool - take on number five seed Peter Wright, who is bidding to claim his first major title.
Van Gerwen remains the favourite to take the title with sponsors BetVictor, at 4/5, with Taylor now 7/3 to continue his incredible Winter Gardens success, with Wright 10/1 and Wade 11/1 to lift the trophy on Sunday night.
Taylor is a 2/9 favourite going into his semi-final with Wade (10/3), while van Gerwen is 1/6 ahead of his clash with Wright, who is 4/1 to reach the final.
The BetVictor World Matchplay will be shown live on Sky Sports in the UK & Ireland and worldwide through the PDC's series of broadcast partners, as well as through www.LIVEPDC.TV for International Pass Subscribers.
BetVictor World Matchplay
Friday July 24
James Wade 16-11 Mensur Suljovic
Phil Taylor 16-8 Dave Chisnall
Saturday July 25 (7pm)
Phil Taylor v James Wade
Michael van Gerwen v Peter Wright
Semi-Finals - Best of 33 legs
* Each game must be won by two clear legs, with up to a maximum of five additional legs being played before the sixth "extra" leg is sudden-death. There will be no re-throw for the bull in this instance. For example, should a Semi-Final (best of 33 legs) reach 19-19, then the 39th leg would be the final and deciding leg.
James Wade v Mensur Suljovic
1-0 - Suljovic misses two darts at double 18 to claim the opening leg, and Wade finishes double ten to break throw immediately.
1-1 - Wade misses five darts at his favoured double ten, allowing Suljovic in to break back by taking out 60 on double ten.
1-2 - Suljovic finishes 101 to move ahead.
2-2 - Wade returns from two misses at double 12 to land double three as he squares the game.
3-2 - Wade pins double top for a 13-darter to break and regain the advantage.
3-3 - Suljovic lands two 180s in the leg, and though he initially misses two darts at double 14, Wade's miss at double eight to finish 96 allows him back in on double seven.
4-3 - Suljovic misses tops to take out 76, and Wade breaks throw once more by taking out 108 on double 18.
5-3 - Wade lands a 171 score before posting double ten to move two legs clear.
5-4 - Double 18 sees Suljovic respond.
6-4 - Wade posts his second 180 of the game before landing tops to regain his edge.
7-4 - Both players land 180s before Wade pins double ten to move three legs clear with another break of throw.
8-4 - Wade finishes 64 with a two-dart combination of treble eight and tops to continue his surge.
8-5 - Wade misses tops to finish 107, allowing Suljovic in to take out 42 on double 14 to win his first leg in four.
9-5 - Wade takes out 86 on double 16 in two clinical darts to move over halfway towards victory.
10-5 - Wade's charge continues with a fourth 180 and a two-dart 74 checkout.
11-5 - Wade finishes 104 on tops to take a six-leg cushion.
12-5 - Double 17 sees the left-hander move four legs away from the semi-finals.
12-6 - Wade misses darts at double ten and five, allowing Suljovic back in to claim his first leg in five on double one.
13-6 - Suljovic misses the bull for a 161 checkout and then is unable to land two darts at double eight, with Wade capitalising on tops.
13-7 - Wade misses tops to allow Suljovic in to hit the same bed to hit back.
13-8 - Suljovic opens with a 180 before finishing 48 on double 14 to continue his revival.
13-9 - The Austrian takes out a fine 116 checkout to win his fourth leg from five as he continues his fightback.
13-10 - Suljovic closes the gap to three legs by finishing 76 on tops.
13-11 - Suljovic wins his fifth straight leg, punishing a miss at tops from Wade by hitting the same bed to take out 56.
14-11 - Suljovic misses his chance to reduce the gap to one leg when he misses double 14 to take out 94, allowing Wade in to finish 74 in two darts to claim his first leg in six.
15-11 - Tops moves Wade a leg away from the semi-finals.
16-11 - Wade finishes a 14-darter on his favoured double top as he secures his last-four place to continue his love affair with the World Matchplay.
Phil Taylor v Dave Chisnall
0-1 - Chisnall finishes 36 to break in the opening leg.
1-1 - Double eight sees Taylor level the contest.
2-1 - Taylor moves ahead by finishing 56 on tops.
2-2 - Chisnall lands a 180 and tops to square the game.
3-2 - Both players land 180s before Taylor edges back ahead.
4-2 - Taylor takes out 130 on the bull to break throw and move two legs clear.
5-2 - Chisnall lands another maximum, but Taylor takes out double nine with his third dart as he takes a three-leg cushion.
5-3 - Chisnall fires in a fourth 180 in five legs before taking out 121 on the bull to respond.
6-3 - The pair trade maximums before Taylor finishes 75 on tops to regain his advantage.
7-3 - Taylor finishes 130 for the second time in the game, this time on double five, to move four legs clear.
8-3 - Double 16 sees Taylor win a third successive leg.
8-4 - Chisnall claims his first leg in four as seven missed doubles across three visits from Taylor allow him back in on double one.
9-4 - Taylor lands a 180 before finishing 68 on tops to regain a five-leg cushion.
10-4 - Taylor moves six legs clear, opening with a 180 before taking out 49 on double 16.
11-4 - Taylor takes out 68 on double two to extend his cushion.
12-4 - Taylor finishes 161 to continue his charge towards the semi-finals.
13-4 - Double 18 moves Taylor three legs away from the win.
14-4 - Taylor finishes 100 as he claims a sixth successive leg.
14-5 - Chisnall lands a 180 and takes out double eight to hit back.
14-6 - Chisnall claims a second successive leg by landing double 16 to continue his revival.
15-6 - Chisnall hits a 180 but misses double 16 to claim another leg, allowing Taylor to finish tops to move to the brink of victory.
15-7 - Chisnall posts his ninth maximum before taking out 66 on double 18 to claim his third leg in four.
15-7 - Taylor misses two match darts, at double 19 to finish 95, and Chisnall lands double ten to keep the game alive.
16-8 - Taylor seals victory in style, opening with a 180 and adding a 177 before finishing double 16 for a 12-darter to book his place in the semis against James Wade.
Latest BetVictor Odds
4/5 Michael van Gerwen
7/4 Phil Taylor
10/1 Peter Wright
11/1 James Wade
Semi-Final Match Odds
2/9 Phil Taylor
10/3 James Wade
1/6 Michael van Gerwen
4/1 Peter Wright
Odds courtesy www.betvictor.com. Please gamble responsibly.