It says a lot about Arsenal's struggles that not even a first north London derby win in more than two years does much for its Premier League targets.
Even after coming from behind to beat Tottenham 2-1, Arsenal is in 10th place and 10 points from the top four.
The more significant results on Sunday in the Champions League chase were victories for Manchester United and Leicester, which both pulled further clear.
United, which is 14 points behind leader Manchester City in second, beat fifth-place West Ham 1-0. Leicester remains a point behind United after routing Sheffield United 5-0. Chelsea is now five points further back in fourth after only managing a draw on Saturday.
Alexandre Lacazette captained Arsenal with Pierre-Emerick Aubameyang out of the starting lineup following a breach of pre-match protocols.
Emile Smith Rowe was unfortunate not to open the scoring for Arsenal when his shot came back off the crossbar with goalkeeper Hugo Lloris beaten. And Tottenham substitute Erik Lamela, on for the injured Son Heung-min, took full advantage with an audacious “rabona” shot from Lucas Moura’s layoff 12 minutes before the break.
Arsenal leveled with a minute of the first half remaining when Martin Odegaard’s shot clipped defender Toby Alderweireld and eluded Lloris.
Lacazette put the hosts ahead from the spot in the second half after being felled by Davinson Sanchez’s untidy challenge before Lamela was dismissed for a second bookable offense for recklessly swinging his arm at Arsenal defender Kieran Tierney
Harry Kane had a late header ruled out for offside and then rattled a post with an 89th-minute free kick in a tense conclusion to the game as Tottenham remained seventh, six points from the top four.
At Old Trafford, Craig Dawson inadvertently headed past his own West Ham goalkeeper — Lukasz Fabianski — in the 53rd minute after Scott McTominay had touched on Bruno Fernandes’ corner.
Fabianski produced a fine save in the first half to tip a shot on to the post from Mason Greenwood, who also hit the woodwork with a 77th-minute strike.
IHEANACHO HAT TRICK
It was a miserable start to life without Chris Wilder for last-place Sheffield United, although Leicester had to wait until six minutes before halftime to find a breakthrough.
Jamie Vardy found space on the left and crossed for Kelechi Iheanacho to tap in his third goal in as many games from close range.
Ayoze Perez extended City’s lead with a fine 64th-minute finish. Iheanacho helped himself to a second five minutes later with a first-time strike from another Vardy cross and then completed a hat trick with an emphatic drive from distance.
Ethan Ampadu turned Vardy’s 80th-minute shot into his own net to nudge Sheffield United closer to relegation and Leicester closer to a return to the Champions League after five years.
Leandro Trossard’s third goal of the season dragged Brighton three points clear of the relegation zone courtesy of a 2-1 win at Southampton.
Lewis Dunk got Brighton off to the perfect start when he headed Pascal Gross’ 16th-minute corner firmly past goalkeeper Fraser Forster.
Che Adams volleyed the Saints level within 11 minutes after Dunk had been unable to cut out Ryan Bertrand’s header back across goal.
But Trossard restored the Seagulls’ lead 11 minutes after the restart after running on to Danny Welbeck’s deft touch.