London - Bafetimbi Gomis gave Swansea an unexpected 1-0 victory over Arsenal on Monday when goal-line technology showed his late header had crossed the line to the surprise of both teams.
It seemed that Arsenal goalkeeper David Ospina had prevented the ball from going into the net in the 85th minute but then referee Kevin Friend looked at his watch and correctly awarded the goal.
As eighth-place Swansea boosted its chances of qualifying for the Europa League, Arsenal missed a chance to strengthen its hold on an automatic passage into the Champions League rather than via a playoff.
Arsenal remains in third place with three games remaining and Manchester United is only two points behind ahead of their meeting on Sunday.
United has played a game more than Arsenal.