West Brom recorded a 2-1 Premier League win over Arsenal at the Hawthorns following Mikel Arteta's first-half own goal and Santi Cazorla's late missed penalty.
Cazorla got a major chance to salvage a draw and spare his compatriot's blushes six minutes from time, but he slipped as he took the kick and skied his effort over the crossbar.
Arteta had previously netted an unfortunate own goal after replacing the injured Francis Coquelin in the 14th minute in what was a remarkable substitute's appearance, with the former Everton midfielder then leaving the pitch injured early in the second half.
Arsenal dominated proceedings in the opening 30 minutes and deservedly went a goal up via Olivier Giroud.
Nevertheless, West Brom bounced back shortly afterwards when James Morrison found the net after a free-kick from Chris Brunt.
Arteta then deflected a cross from the left past Petr Cech to gift West Brom the lead and Arsenal saw their best chance of a draw go to waste as Cazorla's slip meant their six-match unbeaten run came to an end.
Arsenal first threatened in the 14th minute when Alexis Sanchez curled a free-kick over the wall, but Boaz Myhill was equal to the task and made a comfortable save.
Arsene Wenger's men did grab the lead on the half-hour mark from another set piece as Mesut Ozil sent in a superb cross for Giroud and the Frenchman lost his marker before heading home from close range.
The visitors got a fine chance to double their lead shortly afterwards following a good run from Sanchez down the right, but Kieran Gibbs fired his shot just over the bar.
West Brom levelled the scoring in the 35th minute with their first serious chance of the game. Brunt delivered a free-kick into the area and Morrison beat Cech with a subtle volley in the far corner.
The home side then went a goal up shortly before the break via Arteta, who saw James McClean's cross deflect off Cech and onto his leg before slowly crossing the line.
Ozil nearly restored parity immediately after the break when he tried his luck after picking up a cross from the left, but the Germany international was denied by the upright.
Salomon Rondon could have doubled his side's lead after shrugging off Per Mertesacker, but he wildly blasted his volley from inside the area over the bar.
Substitute Joel Campbell should have made it 2-2 midway through the second half after a brilliant pass from Cazorla, but the attacker mis-hit his shot as he tapped wide from close range.
Jonas Olsson nearly netted a third for West Brom after a superb corner from Brunt, but Cech somehow did enough to deny the Swede and keep his side's chances alive.
Cazorla was given the chance to level in the 84th minute following Brunt's foul on Sanchez, but the midfielder lost his footing as West Brom escaped to take all three points.