Giggs, making his 999th appearance in senior football (931 for United, 64 for Wales, four for Team GB), scored the game's second goal to seal three vital points in the race for the Barclays Premier League title.
"There have been times this season, last season and the season before when people were writing him off but he's a top professional," Lou Macari said. "He keeps bouncing back and doing what he's done at QPR. Did he look nearly 40? I don't think so. He flew about the pitch, he got on the ball, his passing was good.
"The biggest indicator as to how good he is: the manager keeps picking him. Sir Alex doesn't mess around here at Manchester United. He lets players go at times when supporters aren't sure why, but he knows things we don't know.
"It's the same for the people he keeps. If he keeps Giggs and Paul Scholes that's because he has a belief that they have something to offer. And they go out onto the pitch and prove the manager's right. To write Giggsy or Scholesy off is a silly thing to do. They can have a poor game, but that happens to the best of players, let alone players approaching 40 years of age."
Denis Irwin added: "He's dedicated, too. You should see him in training. And don't forget, he started as a winger, an out-and-out winger who ran up and down the touchline, scoring goals, creating goals.