Handed his first start in 11 games, the 40-year-old was central to all that was good in United's play and he provided key passes to set up the opening two goals in a 3-0 win over Olympiacos that took United into the last eight.
Giggs, making his 140th Champions League appearance, is second behind former Real Madrid striker Raul, on 142, in games played in the competition.
"I looked at the appearances in the programme before the game," United manager David Moyes said.
"It's incredible the amount of games he has played. I thought Giggsy was fantastic, he really was. The passes he made for the two goals and his general play.
"More importantly his general fitness. You think sometimes that he'd need to come off after 60 minutes but he's a freak he really is. He's something different."
In the latter stages of his career Giggs has been transformed from a pacy winger to a central midfielder. Although the trademark speed has all but disappeared, he is still able to have a major influence in the most important games by virtue of his tactical nous and awareness.
"I just felt after the result to Liverpool I needed him to play a particular role in the centre of midfield for me which he knows and understands and he carried it out perfectly," Moyes said.
One of the only positives in what has been a poor season at Old Trafford has been the emergence of 19-year-old winger Adnan Januzaj and Moyes conceded that the need to identify Giggs's long-term successor was the reason behind the veteran's lack of recent playing time.
"We have to look to see what the others can do. Ryan Giggs is not going to go on forever, we know that," he said.
"So we have to look to find the new Ryan Giggs. It was a big night, we needed it off the back of a bad result and I thought we needed his experience tonight and he certainly showed it."
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- Ryan Giggs