Rusedski, who won the match 6-7, 7-6, 6-1, said: "I knew when I hit it it would be close to or better than my previous fastest. I think the conditions in Asia are the fastest in the world. The ball speed through the air is definitely the fastest I have ever played."
Of the match, the left-hander added: "I really had to wait for my chance to turn it round. I let a close call in the first set tie-breaker get me a little too upset. But I turned a negative into a positive. I regrouped, settled down and found my rhythm in the second set."
Rusedski, who climbed to 75 in the world rankings on Monday, will now meet the Brazilian Gustavo Kuerten, a player ranked 21 places below him, in the last eight. Michael Chang was beaten 6-3, 6-4 by the Czech Martin Damm yesterday.