Arsenal lost 1-0 to Everton in a crucial match for both teams.
James Tarkowski scored the winning goal with a header in the second half.
The defeat prevented Arsenal from going eight points clear of second-placed Manchester City.
The win is Sean Dyche's first as Everton's new manager.
Everton moved out of the bottom three with the victory.
Tarkowski, who was signed by Dyche at Burnley, hopes the win is a turning point for the club.
Early in the game, Eddie Nketiah missed a big chance for Arsenal.
Calvert-Lewin and Saka both had opportunities for either team before halftime.
Arsenal tried to equalize in the second half with Trossard and Saka, but were unable to score.
Everton held on for their first league win since October.