The veteran winger, 35, will now stay with the Old Trafford club until June next year. Giggs, who made his first team debut for United nearly 18 years ago, said: "I feel fit and I'm enjoying my football more than ever.
"This is an exciting young team and the spirit is great in the dressing room. "I want to be a part of that and achieve even more success."
Giggs scored the only goal in Sunday's win at West Ham and boss Alex Ferguson paid tribute to his star.
Fergie said: "Ryan is a true professional of the game. "His lifestyle, the way he looks after himself, his desire to always want to win is a credit to him and also an inspiration to any young kid who wants to become a footballer.
"He is like a young boy in the way that he plays and, although he wants to play every game, he understands that by using his experience when it matters is a benefit to him and the team.
"It would be easy for him to be complacent after all he has achieved but he isn't and that speaks volumes of why the club wanted to extend his services and use that experience."
i feel that he should stay the next season as ferguson assistant and then take over as manager when ferguson retire.. won't that be great?