United's hopes of an 11th league title under the leadership of Ferguson were given a boost at the weekend.
Chelsea and Arsenal fell further off the pace following goalless draws against Hull and Tottenham respectively, while Liverpool needed two goals in the last five minutes to beat struggling Portsmouth.
Aston Villa moved into third spot, five points adrift of United, with a 2-0 success at Blackburn, their seventh successive away win.
Giggs struck in the 62nd minute at Upton Park to give United their seventh away win in the league this season, cutting in from the left, drifting past two West Ham players, before firing past Robert Green.
It was the Welshman's first goal of the campaign and maintained his record of scoring in every Premier League season.
No complacency in title race - Phelan
"I am searching my memory bank for the last time Ryan scored with his right foot," said Ferguson. "I think it was against Coventry 12 years ago.
"Ryan truly is a credit to the game. If anyone wants an example of how to dedicate themselves to football, you could have no greater example than Ryan Giggs."
West Ham boss Gianfranco Zola believes that the 35-year-old winger, who made his first appearance for United in 1990, can play on for "many years".
"I have a lot of admiration for him, he is a fantastic player, and although you are the opposite side, you enjoy players like him," said Zola.
He is one of those players you would love to have in your team
Zola on Giggs
"He is a very good advertisement for football and young players. When somebody has got such a talent it is all down to the desire.
"If you have the desire to carry on playing and challenging yourself all the time, he can play for many years.
"It is up to him. When I was at his age, I just didn't want to give up. I wanted to get better and better. That's why I played for more years.
"Looking at him, he has the same desire. He is one of those players you would love to have in your team."
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.