But despite the crucial win, as the Gunners try desperately to claw their way back in to the top four and snatch Champions League football for next season, Wenger says the three-man tactic is not a long-term plan.
Alexis Sanchez was again influential for Arsenal on Monday as he struck a fine free kick to equalise for Arsene Wenger's side en route to a 2-1 victory at Middlesbrough in the Premier League.
Arsenal beat relegation-embattled Boro 2-1 on Monday to keep alive their faint hopes of a top-four finish.
"Mathematically it is still possible, even if it is hard, but we will give it a go", Wenger said after the victory at the Riverside.
"That shows you that even at my age, you can change", Wenger said after the game when explaining his tactical switch.
"I felt that when we scored we had Arsenal on the back foot and at that point we just needed the ball to fall to us".
"I felt it added a bit more stability on the long balls", Wenger was quoted as saying by the BBC. We were vulnerable. Confidence in life goes away quickly but comes back slowly.
Arsenal face Manchester City on Sunday in the FA Cup semi-finals. "Koscielny was the central one, pulling the strings with us both and telling us where to go and that, so with someone like him and his experience it makes it a lot more comfortable".
Petr Cech was also back from injury, starting for the first time since limping off during the first half of the defeat at West Brom.
"We responded well. I think it was not flawless but the commitment and focus was there. I think we were so low on confidence we needed reassurance on that front". "We need to take responsibility for that", he said.
Alexis Sanchez had given the visitors the lead with a superb first-half free-kick before Alvaro Negredo levelled for Boro five minutes after the break.
Chamberlain, who was arguably the Gunners' best player on the night in an unfamiliar right wing-back role, put the performance down to doing the simple things right. Middlesbrough is second from bottom, six points adrift of safety with six matches left.
The defender said: "It was important to have the three points tonight".
"I thought the players were unbelievable in terms of their effort, attitude and commitment". "They played with such intensity I couldn't have asked for any more from them".