Portugal winger Nani appeared to have scored a 59th-minute winner after goals from Giggs and Javier Hernandez, with David Luiz and Gary Cahill also netting for Chelsea.
However, a late penalty award allowed Eden Hazard to level in added time forcing an additional 30 minutes, and Daniel Sturridge and Ramires wrapped up the victory, with United’s captain also converting from the spot.
“Some of our football was terrific,” said Ferguson.
“In Ryan Giggs, we saw a player of absolute unbelievable proportions in terms of playing the 120 minutes when he’s going to be 39 next month.
“I thought he was a credit to himself. He’s an example to every player on that match – and that includes the Chelsea players.”
Giggs heaped praise on United’s young side, which included Michael Keane and Scott Wootton at centre-half, and is confident the up-and-coming stars will learn from the experience.
“I’m proud of the young players who played though – there were some great performances,” said Giggs. “They will have learnt a lot and you learn more from losing as well.
“You try and take the positives from a game like that but there are a lot of disappointed lads in there and rightly so because they put in good performances.
“But they’ll learn from it and the experience they’ll gain from this is more than they could ever get from a Reserve game.”
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