Arsenal manager Arsene Wenger warned Champions League rivals Tottenham and Chelsea that the Gunners were "ready for a fight'' after they reclaimed third place in the Premier League with a 1-0 win at QPR.
The victory came courtesy of a Theo Walcott goal after just 20 seconds and it lifted Arsenal, who have won six and drawn two of their last eight league games, two points ahead of Spurs and Chelsea.
The three London clubs are engaged in a battle royal for the last two Champions League places. With Arsenal and Spurs both winning today, all eyes now turn to Chelsea and Sunday's trip to Manchester United.
Asked how much pressure Arsenal's triumph now places on Chelsea, Wenger said: "I don't know how much but it puts you under pressure because you have to make a result.
"We are up for it. We are ready for a fight and the team is highly focused to do it. We are on a very strong run. We definitely have a momentum, if you look at the points we have made compared to two months ago. We are going for it and we make the points.
"Away from home recently we have won everywhere - at Fulham, at Sunderland, at Swansea, at QPR. Derbies are difficult to win.''
Walcott's goal, his 20th of the campaign, was the quickest by an Arsenal player in the history of the Premier League and the fastest by anyone in the league this season. The England international struck the post soon after but QPR competed well and in the end Arsenal had goalkeeper Wojciech Szczesny to thank for the win after he brilliantly denied Loic Remy.
"We scored early and started well,'' Wenger said. "He (Walcott) is 24 now. He is a mature player. He has improved his finishing. He has improved his ability to resist pressure from the opponents. It was as similar goal to the one he scored on Sunday against Manchester United. After that I felt QPR played with quality, pride and they were fearless.
"You can see that if they had not had to play with fear in the last few months they had the quality to stay in the Premier League. We needed a special focus today to win the game. The points were vital for us today. We couldn't make any mistakes and that was a bit detrimental maybe to our offensive game.
"They made life difficult for us. We had good focus and good determination. We lacked a few final balls in the final third. Overall, I expected a difficult game and I was not disappointed.''
QPR manager Harry Redknapp was proud of the spirit his relegated side showed in pushing Arsenal so close. "It was an awful start to go 1-0 down within a minute but I thought we showed fantastic spirit today,'' Redknapp said.
"There was nothing in the game. I always felt we were going to get something out of the game and their keeper's pulled off a world-class save late on. I couldn't have asked for more from them. Their heads could have dropped after that start and we could have been beaten by five or six today.
"But we didn't. We got after them, we worked them and I thought it was an excellent performance. I was delighted with the players. People keep on about a lack of spirit. We've lacked people to score goals and maybe a bit of ability in certain areas. It is not a lack of spirit.''
Information from the Press Association was used in this report.