Arsenal manager Arsene Wenger said the whole club are delighted for Danny Welbeck after the striker capped a return from injury with a stoppage-time winner against league leaders Leicester City.
Welbeck entered the fray at the Emirates Stadium in the 83rd minute for his first appearance of the season for the home side and he proved the team's hero when he scored a thumping header in the fifth minute of stoppage time to win the game for Arsenal.
Wenger said it was a relief to see Welbeck return from a knee injury and he only decided to include him in the squad on Saturday.
"In the last two days he was convincing in training. I planned at the start, when I made my press conference on Friday morning, to play him next week," the Frenchman said.
"But in the last two training sessions he was very strong and I decided just in the end to include him in the squad.
"It was a great decision because Danny Welbeck is a great player, and you never know in our job if somebody else had come on would he have scored or not.
"But everybody is extremely happy for him, because he has been out for 10 months - that is an eternity for a player. We work very hard, our medical team, our fitness team, to bring him back so strong."
Wenger said his overwhelming emotion at the end of a rollercoaster 90 minutes, in which Arsenal fell 1-0 behind right on half-time before Theo Walcott's 70th-minute equaliser and Welbeck's late winner, was joy.
"It was happiness, because I think it was a very high level of energy in the game. We put the intensity in from the first to the last minute," he said.
"It was as well a mental test for us, because to find yourself down 1-0 at half-time to a team who defends so well, you need to keep going in your head. And we came back in the second half with relentless energy.
"And we took as well all the risks to win it. We knew a draw was not good enough. In the end it paid off, down to the mental desire of the team to give absolutely everything to win it.