The win puts Arsenal within four points of leader Liverpool, which can restore the gap to seven points when it hosts Wolves at home on Sunday.

It was Arsenal’s first game since leading scorer Kai Havertz sustained a season-ending hamstring tear in training in Dubai, joining striker Gabriel Jesus and winger Bukayo Saka on the long-term injury list.

While the front three of Trossard, Raheem Sterling and Nwaneri struggled to create chances, the latter produced another impressive performance to further boost his rapidly growing reputation.

The teenager hit the woodwork twice, shaving the top of the crossbar from outside the area on the hour mark and then hitting the post with a fierce strike in the 76th. And after scoring two spectacular recent goals against Girona in the Champions League and Manchester City in the league, Nwaneri turned provider this time for Merino’s breakthrough goal.

“He’s an amazing player,” Merino said about Nwaneri, a product of Arsenal’s academy. “I’ve been talking to him the whole season that I needed those kinds of balls when I’m arriving in the box. And he has such a wonderful left foot that he put it right on my head, so I could only score.”