Arsenal and Chelsea played out a thrilling 2-2 draw at the Emirates, with Hector Bellerin's injury-time equaliser denying the visitors a crucial three points.
Jack Wilshere opened the scoring for the north Londoners, before an Eden Hazard penalty tied the game.
The champions travelled to the Emirates with a great record against their hosts in recent years, with the Gunners' 3-0 win in the same fixture last season their only defeat in 12 previous league games.
5 - In all competitions, no team has won more away games at the Emirates Stadium than Chelsea (5, level with Man Utd). Metropolitan. pic.twitter.com/1aaqUowPPY— OptaJoe (@OptaJoe) January 3, 2018
The game started very openly, with both teams having good chances to take an early lead. Alvaro Morata found himself one on one with Petr Cech after a speculative ball upfield from Victor Moses, only to pull his shot wide of the Czech keeper's goal.
From the resulting goal-kick, Arsenal went straight down the other end, where Alexis Sanchez toe-poked a shot towards goal from eight yards, only to be denied by a brilliant fingertip save from Thibaut Courtois.
The Chilean could count himself desperately unlucky not to have opened the scoring, with his effort cannoning off both posts, before finding the grateful hands of the Belgian.
Arsenal v Chelsea though. That Sanchez shot that hit BOTH posts. If that happened in PES/FIFA you would smash the controller off the nearest wall— Ryan Seymour (@ryanseymour1983) January 3, 2018
On the stroke of half-time, the visitors had the best chance of the half, with Eden Hazard leaving three defenders on the floor and back-heeling into the path of Cesc Fabregas, who dragged his effort wide from the edge of the box.
The west Londoners continued the pressure on the Arsenal backline after the interval, with Cech having to make a smart double save; first parrying Eden Hazard's effort after the Belgian broke free of Rob Holding, then reacting quickly to keep out a well-placed Marcos Alonso header.
Moments later, Lacazette slipped away from the Blues' back three and powered a shot at goal, with Courtois making himself big and denying the Frenchman with a brilliant save. It was miraculous that the game was still goalless, with both keepers rescuing their defences on a number of occasions.
Trying to work out how Arsenal vs Chelsea is still 0-0 like... pic.twitter.com/oaoBrwdkIx— bet365 (@bet365) January 3, 2018
The deadlock was finally broken just after the hour mark, when Jack Wilshere fired a rasping drive past the despairing gloves of Courtois. The Englishman's presence on the pitch to score the opener was controversial, given he avoided a second bookable offence for diving mere minutes earlier.
The managers turned to their benches for inspiration, with Arsene Wenger throwing on Danny Welbeck, whilst his opposite number, perhaps surprisingly, withdrew Hazard in favour of Willian. It quickly proved an inspired decision from Conte, as the visitors took the lead with just seven minutes left.
The Brazilian played a sumptuous cross-field ball to Davide Zappacosta, who put a low cross into the box where Marcos Alonso swept home to mad celebrations in the away end.
Despite an onslaught by the hosts, 2017's title winners thought they had done enough to take victory back to Stamford Bridge. Arsenal, however, refused to give in, and in the second minute of injury time, Bellerin fired in from 18 yards to share the points.
From the kick-off, Morata was through on goal yet again, before once again shooting straight at Petr Cech, and Davide Zappacosta hit the crossbar from the rebound. Despite the late drama, the Gunners held on for a valuable point.
The two sides have FA Cup engagements at the weekend before meeting again at Stamford Bridge in a week for the first leg of their Carabao Cup semi-final.