Breaking onto Henrikh Mkhitaryan's pass down the right flank, Hector Bellerin whipped over a cross that ran through to Monreal at the far post, where the left-back lashed home from close-range to cap a fine 17-pass move.
The Gunners trailed again at the Emirates after Marko Arnautovic put West Ham ahead, but levelled through Nacho Monreal before the break and got a slice of luck when an own goal by lssa Diop put them ahead. I think the team played well and I think we were a team that defended well.
Despite the win and the three points, Emery said there were still many things that could improve. We need to continue working to not concede many chances.
Key Opta stats:- West Ham have lost their first three games of the Premier League season for the third time this decade (also 2010-2011 and 2017-2018) after doing so just five times between 1920 and 2010.
In an end-to-end start to the second-half, Pellegrini's men passed up another great chance to re-establish their lead.
Details of the illness were not disclosed by the club as the former German worldwide sat out the Gunners third league game of the season. I said come if you feel better and he felt better. For the second half, we were speaking in the dressing room and to help more inside with two midfielders.
Aubameyang was subdued again, the Gabon global threatening just once from long-range, and when Alexandre Lacazette came on to play alongside at half-time, the French forward immediately looked more unsafe than his team-mate.
One major blow for West Ham was the injury scares to star duo Arnautovic and Michail Antonio, who both had to go off early in north London.
Some sharper finishing from the Austria forward might have seen West Ham take all the points back across London but Arnautovic was very impressive as their focal point, revelling in Arsenal's defensive uncertainty.