The veteran midfielder came off the bench in the victory against Swansea in the manager's final home game in charge and was clearly emotional afterwards, even if he is already looking forward to playing under only his second domestic boss in David Moyes next term.
"Obviously it's been an emotional day," said Giggs. "He's been such a massive part of my life. I met him when I was 13 to what I am now, 39, so it's a long time. Yes, it's an emotional day.
"Not only for my career [has he been such an influence] but for my life. He has been a massive part of my life. He's seen me from a boy to a man and seen me grow. I've seen him mature over the years from the manager I knew when I was younger. He has done everything for me both on and off the pitch."
It was vital for Giggs that United conjured up a late winner to pick up victory and provide a fitting tribute for Sir Alex.
"He said in his pre-match talk that he wanted to make sure we didn't play the occasion but played the game," added the Welshman. "And made sure we did what we've been doing all season, which is winning games.
"I mean it probably summed up the time that he's managed as we've had so many important late goals. He probably didn't expect Rio [Ferdinand] to come up with what was a great finish but it was a fitting end to what was a brilliant career at Old Trafford."
The prospect of working under Moyes thrills Giggs, who recently signed another one-year contract extension to prolong his remarkable career with the Reds.