The French defender's goal aided Arsenal to blow the top four race wide open with the win over Chelsea.

Arsenal skipper Laurent Koscielny has etched his name in the club's history after scoring in his side's win in the London derby on Saturday. While it may have taken a while, the Frenchman became the first defender in the history of Arsenal to reach 20 goals in the English Premier League.

Koscielny continued his streak of scoring in every season since switching to Arsenal in 2010 by bagging a header in the 39th minute. His goal came after Alexander Lacazette had registered Gunners' first goal of the day in a sensational manner.

Despite an injury-plagued career, the 33-year-old center back has made over 330 appearances for Arsenal. Across all competitions, the ex-Lorient starlet has had a decent return of 25 goals.

Addressing BT Sport after the proceeding, Laurent Koscielny was frantic about getting on the scoresheet and also commended his team for collectively working to beat Chelsea.

"I did my work in the gym," he teased in response to how he managed to get on the scoresheet after his spell on the sidelines.

"We know a free-kick or a corner is always important in modern football, the small details. I'm happy to score. "Today we needed to win. We did a mistake last week and it was a game of six points," Koscielny added.

"If we lose, it would be nine points; if we win just three points. We are still in the race for the top four.

"It was important; the commitment was amazing from all the boys. We talked a lot and we showed on the pitch which way we want to go together.

"It is good to play like this. We want to fight for each other.

"When we talk about a clean sheet it is not just about the defenders. We showed everyone working together; the strikers work and help the rest of the team. Then at the back, it is easier to win the challenges.

"It is good for our head – we can keep this [mentality] for the rest of the season.

"This is what the coach asked us to do in the dressing room – [press] from in front. We worked, we fought all the game.

"We are now three points to Chelsea so we are still in the race and we will fight until the end."