By Rob Kelly
The Arsenal left back made a superb last-ditch challenge in injury time to deny Billy Jones and help his side claim the three points that secured Champions League football.
Walcott is delighted to have sealed third place, but says the team owe a debt of gratitude to Gibbs, who came on as a second-half substitute.
"It is a fantastic feeling - we have been hot and cold all season and it doesn't matter how you play, as long as you get the result here," he told Arsenal Player.
"Third is fantastic - you wouldn't have thought that at the start of the season, the way we started off.
"I have to give credit to Kieran Gibbs. The boss has always says, 'you have to be ready when you come off the bench' and Gibbsy made probably made the most important tackle of his career so far.
"You never know what would have happened as we have a world-class keeper behind him and he could have stopped it, but you have to give credit to Gibbo."
Watch the full interview with Theo on Arsenal Player soon.Copyright 2017 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source