Liverpool spent significant periods on the back foot against their vibrant hosts, although Sadio Mane had a goal controversially ruled out for offside and Virgil van Dijk hit the post before captain James Milner clinically pounced on a Bernd Leno error after the hour.
Milner's landmark 50th Premier League goal would not prove decisive, however, as Lacazette latched onto substitute Alex Iwobi's pass, drew Alisson from his goal and finished sublimely.
Jurgen Klopp's side go back to the top of the table for now but will be two points behind Manchester City if the champions beat lowly Southampton on Sunday, while Chelsea can also go above them with three points against Crystal Palace.
Joe Gomez's last-ditch challenge deflected Pierre-Emerick Aubameyang's 14th-minute shot behind, while Mane was flagged offside at the other end when he tapped in after Roberto Firmino hit the post.
A combination of Leno and Shkodran Mustafi prevented Van Dijk from giving Liverpool a 23rd-minute lead when the centre-back stayed forward after a set-piece.
The frantic end-to-end feel continued, with Aubameyang dragging off target from Henrikh Mkhitaryan's backheel, before Mesut Ozil produced an impudent flick of his own from Granit Xhaka's chipped 39th-minute pass for Lacazette to fire wide.
Replicating Alisson's earlier dart from his goal to disrupt a Mkhitaryan aerial attempt, Leno charged haphazardly into Van Dijk in first-half stoppage time and was relieved to see the defender's header bounce to safety off the upright.
Mkhitaryan passed up a couple of shooting opportunities as Arsenal resumed on top but Milner broke the deadlock, smashing home when Leno's fumble from Mane's cross deflected into his path off Rob Holding.
Leno partly atoned for that error by pushing over Van Dijk's 74th-minute header, by which stage Arsenal's earlier poise and threat looked to have dissipated. Lacazette had other ideas eight minutes from time.
What does it mean? Emery's men ready for Champions League push
Much was made of the relatively favourable run of fixtures across which Arsenal compiled a 13-match unbeaten run heading into the Liverpool encounter, but this performance bore little resemblance to the frantic mess of the defeats to Manchester City and Chelsea back in August. Unai Emery's Arsenal showed they can hang with top-class opposition.
Xhaka shows his class in favoured role
A whipping boy when Arsenal fell short against Premier League heavyweights last season, Switzerland international Xhaka displayed all of his enviable array of qualities, often leaving Liverpool disorganised in central areas as a result. He broke up play judiciously, gaining possession 15 times without ever resorting to the rashness that makes for a weighty disciplinary record. Xhaka's passing range was to the fore as well over the course of 90 minutes he appeared to enjoy, now freed from his recent toils as an emergency left-back.
Leno woe undermines Gunners
Even allowing for some erratic Mkhitaryan contributions, Arsenal's outfit players were a credit to their head coach. The same could not be said for Leno. His challenge on Van Dijk might have resulted in either a goal or a penalty for Liverpool and the attempt to catch Mane's centre while at full-stretch could have been a game-settling howler.
Key Opta Facts
- Liverpool are unbeaten in their opening 11 matches to a Premier League campaign for the first time since 2007-08.
- Arsenal have won more points from losing positions than any other Premier League side in 2018-19 (8).
- Arsenal are winless in their past seven Premier League meetings with Liverpool (D3 L4).
- Arsenal have not led at half-time in any of their 11 Premier League matches this season. However, the Gunners have scored more goals after the break than any other side (19).
- James Milner's strike for Liverpool was his first from open play in the Premier League since March 2016 vs Manchester City – ending a run of eight successive strikes from the penalty spot in the competition.