Arsenal have stumbled in their Champions League qualification quest after an uninspiring 1-0 English Premier League loss at Southampton.
Tottenham’s shock 1-0 home defeat to Brighton in Saturday’s earlier clash gave the Gunners a golden opportunity to draw level on points with their fourth-placed north London rivals.
But Mikel Arteta’s men failed to capitalise at St Mary’s as Jan Bednarek’s strike on the stroke of half-time condemned them to a fourth defeat from five games.
Arsenal retains a game in hand on Spurs, albeit a tricky trip to Chelsea, while their latest slip-up provides further encouragement for fellow top-four hopefuls Manchester United and West Ham.
Victory for Saints ended a five-match winless league run to boost their aspirations of a top-half finish.
Leandro Trossard’s 90th-minute goal iced Brighton’s 1-0 victory at Tottenham on Saturday to halt the north London club’s resurgence.
Tottenham had won five out of their last six matches.
“I don’t think we were right really from the beginning,” Tottenham defender Eric Dier told BT Sport.
“We were a bit slow in moving the ball. We struggled to create chances and we conceded a sloppy goal at the end. Today was definitely a slip-up.”
Meanwhile, Cristiano Ronaldo sealed a hat-trick with a stunning free-kick in the 76th minute to give Manchester United a 3-2 win over Norwich and boost their Champions League hopes.
United overcame a day of protests at Old Trafford to move past Arsenal into fifth place, three points behind Tottenham.
United blew a two-goal lead after last-placed Norwich fought back to tie the game on goals by Kieran Dowell and Teemu Pukki.
But the day belonged to the Portugal superstar, who recorded the 50th hat-trick of his professional career for his club and 60th overall.
It provided a happy ending for a game that started with thousands protesting against United’s owners, the Glazer family, and continued throughout the encounter.
In other results, Watford’s already-slim survival chances took a heavy blow when Pontus Jansson’s last-gasp winner secured a 2-1 victory for Brentford.