Arsenal boss Arsene Wenger said his side's desire kept them in the FA Cup as they turned around a two-goal deficit to beat Aston Villa 3-2.
Arsene Wenger speaks to ESPN
And Robin van Persie said he was grateful for "a crazy six minutes'' which saw Arsenal claim their place in the fifth round.
Wenger told ESPN: "We wanted to stay in the cup. I felt 2-0 was very harsh for us at half-time, but it was a question of scoring the 2-1 [goal] and keeping our structure and not doing anything silly. Fortunately we got an early 2-1 [goal].''
With both Manchester clubs out of the tournament, it could be a good opportunity for the Gunners to end their trophy drought.
Wenger added: "It is an opportunity but you can see today how difficult the games are. But we played at home, we wanted to qualify and we did it. I was very impressed because I felt that when you come out of a bad period like we are, and you are 2-0 down, you can feel sorry for yourself or you can show you have the mental qualities to play for this club.
"I was very proud the team came out playing on all cylinders and showed they are not ready to lie down. That is was a good test to show that we had the mental qualities to come back. On the other hand it was important that we didn't panic.
"To concede a goal just on half-time for 2-0 was a difficult blow, but we responded very well against Manchester United here and we did it again today. Overall it was a classic FA Cup tie in England: 2-0 down and coming back, we had to fight to score three goals and we did it well.''
Wenger had been given a rough ride by some home supporters following last weekend's 2-1 defeat by United, which was a third straight in the Premier League to lose ground on the top four.
The Arsenal manager said: "I felt they were quite positive [today] compared to last time. I am sad we cannot always keep them happy, the only thing we can do is show the spirit that we showed today.
"I just want to do well for this club that I love. I understand that people question my decisions, but I wouldn't understand if they questioned my commitment and my dedication. The rest I understand, that sometimes people are not happy with my decisions.''
Wenger believes this result could transfer through to the league.
"I hope that it convinces the team we have the required qualities and we can transfer that to the Premier League,'' he said.
With the transfer deadline looming this week, Wenger said: "I cannot say nothing will happen but it would be a little bit of a miracle now. For us the biggest thing is to get our players back.''
One of those injured players is Jack Wilshere, who has yet to play this season, with some reports suggesting he will not feature at all now this campaign.
Wenger said: "I have spoken to Jack today. His morale is strong. Hopefully we will have good news. The first news we have had is better than expected. He is not in a boot, but I don't know more. There will be more tests this week.
"I do not know yet when he will start training. I would not like to make any mistake in my statement because I did not speak to the medical people today.''
Van Persie added: "It was very important. At 2-0 down, it's always going to be a hard task to come back. But a crazy six minutes in the second half changed the game. Credit to the team. We all did it. Credit to all of them because we worked hard and we're still in it.''
Van Persie said the team still believe they can win silverware this season.
"[It's] another chance, because we're still in the Champions League,'' he said. "We worked so hard. We are excited for the next round.''
Walcott, whose goal came as a defensive clearance ricocheted off him into the net, said: "We need a bit of luck. Hopefully the luck's changing. The team worked so hard. This cup means so much to us. We want to win this trophy. We need to show the fans we're ready It shows we've got great characters in the dressing room.''
Villa boss Alex McLeish felt the result was harsh on his side.
"We still had chances to at least get a draw,'' he said. "A terrible eight minutes we had. I thought the second penalty was a bit harsh. We've just got to take it on the chin and move on to the next league game.
"The [first] goal gave them (Arsenal) a huge lift. I didn't think they looked as if they could score but that goal gave them a huge lift. But I expected a reaction from Arsenal.
"Maybe we didn't defend as compactly [in the second half]. The [Arsenal] midfield started to get a bit of possession and that gave them the ascendancy.''