Tottenham missed the chance to go top of the Premier League as Alexis Sanchez salvaged a 2-2 draw for 10-man Arsenal at White Hart Lane on Saturday.
The Chilean struck with 14 minutes to play after goals from Toby Alderweireld (60) and Harry Kane (62) had overturned Aaron Ramsey's (39) first-half opener.
Spurs appeared to be heading for three points when they scored two in quick succession shortly after Francis Coquelin had been sent off for a second yellow card on 55 minutes.
But Sanchez's strike earned a share of the spoils and Ramsey nearly grabbed the winner for the Gunners, only for Kevin Wimmer's last-ditch challenge to deny the Arsenal midfielder.
The draw opened the door for Leicester to extend their lead at the top and they beat Watford on Saturday Night Football, with Tottenham now five points behind the Foxes and Arsenal a further three back.
Arsene Wenger handed Mohamed Elneny his full Premier League debut as both managers made four changes from their midweek defeats, but it was Tottenham who started the brighter.
Kane drew an early save from David Ospina, in for the injured Petr Cech, while Dele Alli and Erik Lamela both threatened to get behind the Arsenal defence.
The Gunners rarely looked dangerous in attack early on and nearly fell behind on 25 minutes when Kyle Walker's driven cross was turned goalwards by Lamela, but Ospina reacted brilliantly to keep it out.
The first-half became scrappy as the interval neared, and the visitors stunned the home crowd as Ramsey's back-heel finish put them ahead with their first shot on target.
Danny Welbeck broke clear down the left and crossed for Hector Bellerin, who teed up Ramsey to guide past Lloris.
The goal gave the Gunners a lift and they threatened to double their lead before the break. Alexis Sanchez's cut-back went untouched before Lloris held Welbeck's diving header, and they looked comfortable until Coquelin's red card on 55 minutes.
The midfielder was booked for handball in the first half, and picked up his second yellow from referee Michael Oliver for a lunge on Kane.
The man advantage sparked Spurs into life, and they equalised through Alderweireld five minutes later. It was a carbon copy of a chance moments before for Kane, but while Ospina brilliantly denied the Spurs striker then, he could do little to prevent Alderweireld from blasting home from close range.
Kane capped a remarkable turnaround with Tottenham's second two minutes later, curling a stunning strike in off the post for his 14th goal in 18 Premier League London derbies.
And the hosts looked comfortable before Sanchez equalised out of nothing. The forward, who had not scored in the league since October, latched onto Bellerin's pass and calmly slotted past Lloris.
Eric Dier was fortunate to avoid a second yellow card for a pull on substitute Oliver Giroud's shirt as Spurs pushed for a winner, and Alli drew a smart stop from Ospina with a long-distance effort.
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Arsenal retained a threat and Lloris was called into action to punch clear Sanchez's dipping free-kick, before Gabriel was fortunate to avoid a spectacular own goal when his skewed clearance landed on the roof of the net.
The final chance of a dramatic encounter fell to the visitors, but Wimmer's desperate lunge halted Ramsey with the Welshman bearing down on the Spurs goal.
Both teams will need to dust themselves down quickly, with Wenger's side next in action against Hull in their FA Cup fifth-round replay, while Tottenham travel to Dortmund for their Europa League last-16 clash on Thursday.
Tottenham: Lloris (6), Walker (7), Alderweireld (7), Wimmer (7), Rose (6), Dembele (6), Dier (6), Lamela (6), Eriksen (6), Alli (6), Kane (7)
Subs used: Son (6), Mason (6), Davies (6)
Arsenal: Ospina (8), Bellerin (6), Mertesacker (6), Gabriel (6), Gibbs (6), Coquelin (4), Elneny (7), Ramsey (7), Ozil (6), Sanchez (7), Welbeck (7)
Subs used: Giroud (6), Flamini (6), Campbell (6)
Man of the match: David Ospina