The match ended in a 1-1 draw, despite a host of chances from United. Giggs scored United’s only goal with a header.
“With so little time to go I suppose we’ll settle for draw but with the way we played and our tempo in the second half, we probably deserved to win.” Giggs told Sky Sports.
“It was a disappointing first half for us but the performance in the second half was much better. We came out and worked really hard and kept them pinned down.
“We knew chances would come. We knew we just had to keep the crosses and the one-twos going, keep the tempo up and it would come.”
Giggs scored his goal on a header after Celtic goalkeeper Artur Boruc only managed to parry a shot by Cristiano Ronaldo.
“It’s always worth following up a shot like that with the ball moving all over the place,” Giggs said.
“I just gambled and it fell right onto my head.”