As Groups E-H concluded on a dramatic Day Four at the Aldersley Leisure Village, the biggest story of the night saw Aspinall reel off four straight legs from 2-1 down to eliminate World Champion Wright.
Wright - without his trademark painted head as wife Jo continues to receive treatment following a recent operation - required three legs to book his place in the knockout stages despite two opening Group E wins.
However, the Scot was punished for squandering two darts at tops for a 3-1 lead in a crucial fourth leg, as Aspinall won the last four legs without reply to confirm his progression.
Aspinall followed up legs of 14 and 13 darts with a 106 checkout to lead 4-2, and despite spurning five match darts in an edgy conclusion, he regained his poise to wrap up proceedings via double eight.
"I'm so happy to get through and I can't believe I've topped the group," admitted Aspinall, who will meet Jermaine Wattimena for a place in the quarter-finals.
"Peter is going through a tough time at the moment. I don't think his head was in the game and I give my best wishes to Jo, but I had to go up there and do my job."
Aspinall's 5-2 success saw him top Group E on leg difference, and the Stockport star advances alongside debutant Alan Soutar, who defeated Fallon Sherrock 5-2 earlier in the night.
Sherrock opened up an early 2-1 lead and posted back-to-back 180s in leg six to threaten a nine-darter, but a brilliant 132 finish from the Scot in the very same leg catapulted him to victory.
Soutar knew that a Wright victory or a three-leg win for Aspinall would see him through, and following a nervous wait, the firefighter was able to celebrate another landmark moment in his career.
"Watching that match backstage was the worst feeling I've ever had in darts - it was horrible!" admitted Soutar, who will now play Jonny Clayton in Thursday's second round.
"The Grand Slam was a free-roll for me and I'm now in the world's top 40 after less than two years on the tour, so I'm absolutely delighted."
Elsewhere, Van Gerwen sealed top spot in Group G despite succumbing to an inspired Ross Smith in arguably the match of the tournament so far.
2022 Cazoo Grand Slam of Dartsm Tuesday November 15, Groups E-H Third Matches:
- Jermaine Wattimena 5-1 Leonard Gates (F)
- Damon Heta 5-2 Jonny Clayton (F)
- Nathan Rafferty 5-4 Luke Woodhouse (G)
- Ross Smith 5-4 Michael van Gerwen (G)
- Alan Soutar 5-2 Fallon Sherrock (E)
- Nathan Aspinall 5-2 Peter Wright (E)
- Scott Williams 5-3 Ryan Searle (H)
- Josh Rock 5-3 Luke Humphries (H)
Smith was assured of qualification before his tie against Van Gerwen following Luke Woodhouse's defeat to Nathan Rafferty, and he produced a blistering display to prevail in a nine-leg epic.
The European Champion stormed into a 3-0 lead with legs of 13, 12 and 14 darts, although Van Gerwen - aided by a spectacular 145 checkout - replied with four straight legs to seize control.
Van Gerwen almost wrapped up victory with a spectacular 146 checkout in leg eight, but after forcing a decider, Smith fired in a record-breaking ninth 180 and landed double eight to round off a classic.
"I wanted to show everyone what I can do against the best in the world," said Smith, who averaged 108 and hit a maximum in every single leg.
"Hopefully I can kick on now. I'm loving my darts and I'm so happy with life in general, so I just want to keep going.
Woodhouse saw his qualification hopes dashed in a thrilling nine-leg affair against Nathan Rafferty, despite averaging 101, crashing in five 180s and converting the first 170 finish of the tournament.
Wednesday November 16 (1900 GMT)
- Raymond van Barneveld v Simon Whitlock
- Michael Smith v Rob Cross
- Danny Noppert v Gerwyn Price
- Dirk van Duijvenbode v Joe Cullen
In Group H, emerging Northern Irish star Josh Rock joined Luke Humphries in the last 16 after running out a 5-3 winner in a captivating showdown between the pair.
Scott Williams posted a stunning 107 average to come through a high-quality clash against Ryan Searle in the other Group G tie, registering six 180s and two 11-darters in the process.
That result meant that Rock needed three legs to confirm his progression, yet he was forced to a survive a scare midway through the contest after Humphries squandered two darts at double for a 4-1 lead.
Rock claimed his all-important third leg with a brilliant 121 combination in leg six, and back-to-back 15-darters capped off another imperious display from the 21-year-old.
"I believe I can win this tournament," insisted Rock, who will play three-time Grand Slam champion Van Gerwen in a huge last 16 tie on Thursday night.
"It will be a fantastic match. I've never played Michael before - he's the second best player of all time in my opinion, but I'm not scared of playing him."
Thursday November 17 (1900 GMT)
- Nathan Aspinall v Jermaine Wattimena
- Jonny Clayton v Alan Soutar
- Michael van Gerwen v Josh Rock
- Luke Humphries v Ross Smith
Earlier in the night, Wattimena joined Clayton in advancing through Group F, punishing a profligate display from North American Champion Leonard Gates to complete an emphatic 5-1 victory.
Wattimena sealed the deal with a clinical 108 kill, and this result meant that Damon Heta needed to whitewash Clayton to keep his Grand Slam dream alive.
The Australian was unable to produce the heroic escape act, although he bowed out on a high by averaging 93 and landing three 180s to inflict Clayton's first defeat of the campaign.
The last 16 of the Grand Slam gets underway on Wednesday night, as reigning champion Gerwyn Price plays UK Open winner Danny Noppert, while 2012 champion Raymond van Barneveld plays Australia's World Cup hero Simon Whitlock.
Elsewhere, former World Cup of Darts partners Michael Smith and Rob Cross collide, while Masters champion Joe Cullen meets Dutch star Dirk van Duijvenbode for a place in the last eight.