Lewis had been flawless with his finishing as he won four successive legs to take a 4-1 lead in his clash with Wade, only to let 2009 champion Wade back into the contest as the left-hander won four of his own to move 5-4 up.
Lewis, though, kicked off the tenth leg with a 180 and added a 177 before taking out 144 with two further treble 20s and double 12 to complete his fourth televised nine-darter, and the first in the Premier League since 2012.
He went on to take the game's next two legs to secure a victory from the game, as Wade wired the bull to secure a point in seeing the two-time World Champion consolidate his spot inside the Play-Off positions.
"I'm lost for words - it's a really special moment for me," said Lewis. "I took a 4-1 lead and I thought I was cruising, and before I knew it James was 5-4 up, he dug in really well and fair play to him.
"It got to the stage where I needed a massive leg, and I didn't expect the nine-darter to come from it. To hit the nine-darter in front of this crowd is unbelievable, brilliant. I'm over the moon.
"I've hit a couple of nine-darters recently and I'm really pleased with my form. It was a massive game because Wadey's on my tail and I knew I needed a win."
The night also saw six-time Premier League champion Phil Taylor move four points clear at the top of the table as he defeated 2014 winner Raymond van Barneveld 7-5 in a see-saw contest to extend his unbeaten run to 11 matches.
After opening the match with a 180 in a 13-darter to break throw, Taylor opened up leads of 2-0, 5-1 and 6-2 as he secured a point to extend his unbeaten run this season to 11 matches.
Van Barneveld, aided by a 106 finish, took three legs to fight back and force a deciding leg in which both players landed 177 scores before a 171 from Taylor helped give him the breathing space to finally secure victory on double two.
"It's another two points for me and I'm closer to the Play-Offs, which is so important for me," said Taylor. "Barney stuck in there and came back well, and he played really well.
"He put me under pressure so I'm pleased to have got the win - I knew that the worst outcome going into the last leg was a draw but I had the throw and the 177 and 171 were big shots."
Van Barneveld bounced back later in the evening to defeat Robert Thornton 7-4, with the Scot enduring a mixed night in Belfast after opening the night with an outstanding 105 average as he stormed past Peter Wright 7-5.
The night's other game saw world number one Michael van Gerwen and reigning Premier League and World Champion Gary Anderson share the points in a high-quality draw, with the Dutchman averaging 110.55 to the Scot's 108.24.
However, neither player was able to secure a break of throw in a fast-paced contest, with Anderson producing a key 119 checkout in the tenth leg before the pair traded 13-darters to share the spoils.
"We didn't give each other many chances but I think it was a good result for both of us," said van Gerwen, who has now drawn four of his last five games but remains unbeaten in ten weeks. "I think it was a fantastic match for everyone to watch."
Anderson, who hit six doubles from seven attempts, added: "It was a good game but neither of us could get the break, but I'm happy with where I'm sitting in the table. Michael's at the top of the tree at the moment but he's not having it all his own way and we're on his tail."
The Betway Premier League continues next Thursday with Night 12 at the BIC in Bournemouth, where van Gerwen and Lewis will face each other in a tasty fixture as the pair both compete twice on the south coast.
Betway Premier League
Night 11 - April 14
The SSE Arena, Belfast
Robert Thornton 7-2 Peter Wright
Raymond van Barneveld 5-7 Phil Taylor
James Wade 5-7 Adrian Lewis - Adrian Lewis hits nine-dart finish
Michael van Gerwen 6-6 Gary Anderson
Raymond van Barneveld 7-4 Robert Thornton
Best of 12 legs
Robert Thornton v Peter Wright
1-0 - Double 18 gives Thornton an ideal start with a 13-dart finish.
2-0 - Thornton opens with a 180 before being given a reprieve when Wright misses two darts at tops, allowing his rival back in on double ten.
3-0 - Wright fires in a 180 as he bids to break back, but Thornton takes out 113 for a 12-darter to continue his confident opening.
3-1 - Wright takes out a fine 120 finish to claim his first leg of the contest.
4-1 - Thornton finishes 71 on tops to regain his three-leg cushion.
5-1 - Wright tees up a possible nine-darter by opening with two 180s - Thornton replying with a maximum of his own - but the world number five misses out on a perfect leg and then misses four darts at double 18 to allow his rival in on tops for a break of throw.
6-1 - A 14-dart finish for Thornton secures him a minimum of a point, as he lands double ten.
6-2 - Wright opens with his fourth 180 before hitting tops to retain his hopes of snatching a draw.
7-2 - Thornton completes a superb win by finishing tops for a 14-darter, ending with a 105.61 average as he claims his second victory of the season.
Raymond van Barneveld v Phil Taylor
0-1 - Taylor kicks off the match with a 180 before punishing van Barneveld for three missed doubles - one at the bull and two darts at double eight - by landing double 12 for a 13-darter to break throw immediately.
0-2 - Taylor misses the bull for a 121 finish, but returns on double eight to win a second leg.
1-2 - van Barneveld lands tops to get off the mark.
1-3 - Taylor kicks off the leg with a 180 before hitting a third-dart double 16 to claim his third leg.
1-4 - Taylor opens with a 174 score and takes out 87 for a superb 11-darter to break throw for a second time as he opens up a three-leg lead.
1-5 - Taylor takes out 68 on double four to move further towards the winning line.
2-5 - van Barneveld lands a 180 - his first of the match - and posts double eight to hit back with his leg in four.
2-6 - Taylor lands a 180, and when van Barneveld is unable to land the bull to complete a 121 finish the Stoke ace steps in to finish 80 on double ten for a 14-darter to secure a point.
3-6 - Double nine sees van Barneveld hit back to keep his hopes alive of claiming a draw.
4-6 - Taylor kicks off with a 174 score for the second time in the match, but misses two darts at double 16 to complete the win as van Barneveld steps in to take out 61 on double four.
5-6 - van Barneveld takes out a brilliant 106 checkout - with Taylor waiting on 32 - to send the match into a decider.
5-7 - The pair trade 177 scores as the tension mounts, before Taylor lands a 171 score to leave 32 after nine darts - giving him the breathing space to miss four more match darts before posting double two to secure both points.
James Wade v Adrian Lewis
1-0 - Lewis lands the game's first 180, but Wade finishes tops for a 14-darter to claim the opening leg.
1-1 - Lewis takes out 108 on double 16 to level.
1-2 - Lewis breaks throw on double 16 to move ahead.
1-3 - Wade misses a dart at tops to finish 82, and Lewis' flawless finishing continues as he takes out 76 on double eight to win a third successive leg.
1-4 - Lewis takes out another 76 checkout, again in two darts on double eight, to break throw again and move three legs clear.
2-4 - Lewis misses his first three darts at a double, at tops, double ten and double five, before Wade breaks throw on double 18 to respond with his first leg in five.
3-4 - Wade kicks off with a 180, but misses double 11 for an 84 finish only for Lewis to be unable to land double 12 to take out 101, allowing the left-hander back in on double four to claim a second successive leg.
4-4 - Lewis' double trouble continues as he misses double top and ten, and Wade finishes 101 on double 12 to level the game.
5-4 - Wade finishes 121 on the bull to regain the lead, winning his fourth successive leg.
5-5 - ADRIAN LEWIS HITS NINE-DART FINISH! Lewis opens with a 180 and lands a 177 before taking out 144 with two treble 20s and double 12 to complete a brilliant perfect leg, the first in the Premier League since 2012!
5-6 - Double nine sees Lewis break throw to secure at least a point.
5-7 - Wade wires the bull for a 161 finish to claim a draw, allowing Lewis back in on double ten to secure the victory.
Michael van Gerwen v Gary Anderson
1-0 - van Gerwen makes a superb start by finishing 82 for a 12-darter.
1-1 - Anderson levels with a 14-darter by finishing 52.
2-1 - van Gerwen lands two 180s in a 12-darter as a 64 finish edges him back ahead.
2-2 - van Gerwen opens with 180 and 140 as he seeks a break of throw, but Anderson holds firm to finish double 18 for a 13-darter.
3-2 - van Gerwen adds another 180 and a 68 finish to hold throw once more.
3-3 - Anderson levels on double 12.
4-3 - The pair trade 180s before van Gerwen finishes an 11-darter on double 16.
4-4 - Anderson finishes 64 on tops to square a tight contest once more.
5-4 - van Gerwen lands another 180 before double 16 sees him edge back in front.
5-5 - Anderson takes out a superb 119 finish - with van Gerwen waiting on 48 - as he responds.
6-5 - van Gerwen secures a minimum of a point with a superb 13-darter, landing double 16.
6-6 - Anderson hits a 180 before claiming a draw with a 13-darter of his own, as tops seals a share of the spoils.
Raymond van Barneveld v Robert Thornton
1-0 - van Barneveld claims the opening leg on double top.
1-1 - Double five sees Thornton level.
2-1 - van Barneveld lands a 180 and double 16 in a fine 11-dart leg.
3-1 - van Barneveld hits another 180 before punishing Thornton's miss at double 16 - for a 143 finish - to land double eight for a break of throw.
3-2 - Thornton opens with a 180 as he breaks throw.
3-3 - An 89 finish sees Thornton level the game.
4-3 - Thornton hits his second 180 of the game, but misses five darts at doubles to punish three misses from his rival, as the Dutchman returns on double two to edge back ahead.
4-4 - Thornton levels with a superb 101 checkout.
5-4 - van Barneveld hits a maximum and finishes double 12 for a fine 13-darter to regain the edge.
6-4 - van Barneveld wires the bull for a 126 finish, but returns on double eight to secure at least a draw.
7-4 - The Dutchman adds another 180 before sealing victory with a 91 checkout.