Viktor Gyokeres warned Arsenal must "be at our best" in order to get past Atletico Madrid in their Champions League semi-final second leg.

Atletico and Arsenal played out a 1-1 draw at the Riyadh Air Metropolitano, in a first leg that was overshadowed by penalty drama.

Gyokeres converted from 12 yards after being clumsily bundled over by David Hancko, before Julian Alvarez rifled home from the spot after Ben White's handball.

But Arsenal were denied a penalty following a VAR review after Hancko was deemed to have made minimal contact with Eberechi Eze.

The Gunners had struggled to impose themselves in the second half against Atletico before that, as they only got two of their 11 shots on target, and created just 1.5 expected goals (xG), with that total inflated by the spot-kick.

Arsenal, despite equalling their longest-ever unbeaten run in the European Cup/Champions League, have only won two of their last eight matches in all competitions (D2 L4).

And Gyokeres noted that while they did well to come away from the away league on level terms, there needs to be an improvement next week.

"I think in the first half we controlled the game quite well," he told TNT Sports.

"We had a few good opportunities and managed to score. In the second half, they started much better and managed to get a goal and then, towards the end, we had a few okay chances. Overall, it was a tough game; it's a tough place to come, but it's only half-time.

"It was not easy once they scored. They have the crowd here. We tried to play and get that momentum back that we had in the first half. Towards the end, we did, but it was a tough second half.

"We know when we play at home with our fans, it's going to be different. We just have to do our job and be at our best."

Atletico's xG of 2.2 in this game was the second-highest by a team against Arsenal across all competitions this season, only behind Aston Villa in December in the Premier League (2.5).

Arsenal held up against Atletico's pressure, with Antoine Griezmann also striking the woodwork, and Mikel Arteta remains optimistic ahead of the return leg.

"There are a lot of positives. A lot of very good things that we did," he told TNT Sports.

"We knew we would have tough moments. Their home record is once again [strong].

"We are in an incredible position. We have to play in front of our people. It is in our hands."