Arsenal were denied a "clear penalty" in their 1-0 defeat to Sheffield United and did not deserve to lose the match, according to boss Unai Emery.

Lys Mousset scored the only goal in Monday's Premier League clash at Bramall Lane to earn the hosts a famous victory on his first league start.

The 23-year-old profited from some slack defending from a corner to punish Arsenal, who had previously gone eight matches unbeaten in all competitions.

Defeat for Arsenal cost them the chance to move up to third in the table, but Emery felt his side were denied an obvious penalty for John Egan's shirt pull on Sokratis inside the opening seven minutes.

"We did not deserve to lose and we conceded a lot of corners in the first half and they scored in one action," he told Sky Sports. "Above all, we have to improve by not allowing balls like that.

"When we have our opportunities to attack, we created more chances than them but did not score today.

"We deserved more from the game but they have conceded the least goals in the Premier League and it was going to be difficult if they scored first. We tried in the second half, created three good chances to score.

"There were two key moments in the match - one was their goal, and the second was a very clear penalty for us for a foul on Sokratis. It was very clear."

Bukayo Saka was later cautioned for a perceived dive inside the box under pressure from Enda Stevens, five minutes after Mousset's winning goal from close range.

"Saka drives forward but I do not know if it was a penalty," Emery said. "It is a hard action for a yellow card. With VAR, the foul on Sokratis should have been reviewed. It was clear but we have to accept it.

"We did not deserve to lose and we will think about where we can improve. When we were losing 1-0, we controlled the game and defended well but they had a lot of players in their box so it was difficult to achieve attacks."

Arsenal are now winless in four league games away from home since the opening weekend and Emery added: "We have challenges in each match.

"Tonight we had a big challenge to get the three points. We are playing some young players who are taking experience but the most important thing is to win. The result is one thing, but we can analyse positively."