Having clinched the year-end world number one honours earlier in the $3.65 million tournament, Roddick is closing in on his seventh title of the season and winner's purse of $1.4 million.
Roddick's win sets up an intriguing semi-final showdown with Roger Federer, the raw, brute power of the U.S. Open champion against the finesse and all-round game of the Swiss Wimbledon champion.
The other semi-final will also feature a grand slam winner, Australian Open champion Andre Agassi taking on the surprise player of the tournament, Rainer Schuettler of Germany.
