Olivier Giroud apologised for his mindless red card in Arsenal's 2-1 Premier League victory over QPR, with Arsene Wenger admitting the France striker deserved to be sent off.
Giroud was dismissed early in the second half at the Emirates Stadium for head-butting Nedum Onuoha right in front of referee Martin Atkinson and Wenger gave his forward an icy glare as he stalked off the pitch.
Arsenal, who had opened the scoring through Alexis Sanchez, added a second through Tomas Rosicky but faced a nervy finish when Charlie Austin pulled one back from the penalty spot.
"It was a deserved red card. Madness is a strong word -- he didn't kill him. But he touched him and should not have done it. He should have been in control," said Wenger, who confirmed that Giroud has apologised.
"Olivier Giroud knows he made a mistake and I know him well enough to think that he will not do it again.
"He told me he was pushed in the back and that projected him into the keeper. Usually he's a guy who's in control of his response."
The Arsenal boss admitted he will admonish Giroud in private for his dismissal.
"Yes, of course," said Wenger. "He knows that he has made a big mistake today. It was deserved, he didn't control himself and that of course, is a straight red.
"Of course [it was costly], it changed the game's dynamic completely. We were completely in control of the game, not in trouble, and suddenly we were down to 10 men and only one-nil up.
"We threw our bodies in after that. We knew we had to do that, and what I feel is that in the last four, five weeks we have defended with more resilience, even if we conceded from a set-piece to draw against Liverpool.
"Overall I think defensively we are better."
Giroud now begins a three-match suspension that includes Premier League appointments with West Ham and Southampton and the FA Cup tie against Stoke City.
"Honestly, you never need that. In my job you sometimes have to deal with the strengths and sometimes the mistakes of people," Wenger said.
Wenger celebrated his 400th Premier League victory and 600th as Arsenal manager, but was almost denied the milestones when QPR poured forward in the closing minutes.
"We were nervous and the opponent pushed forward. Our game is about psychology and the mental aspect. In the final part of the game when the result is not settled, it's always very important," Wenger said.
Chile striker Sanchez missed a penalty, scored the opener and then laid on the winner for fit-again Rosicky, drawing praise from Wenger.
"He gives you always hope he can deliver a goal chance, and he did that again today," Wenger told BT Sport.
"He's always efficient at the end of the game and he had a big effect again."
"We are not going to comment on the referee's decision too much, but to be fair I think it was a bit hard on us, but we'll forgive him, it's Christmas.
"It was great character of the team today until the last minute."
Information from Press Association was used in this report.