The 18 year old captured his second ATP Tour title in as many weeks.
The Russian is one of those fancied to wrest the title from world number one Roger Federer this time.
World number one and defending champion Roger Federer won an epic 20-18 tie-break to seal a 6-3, 7-6 win over Marat Safin and place in the Masters Cup final.
The semi-final line-up for the Masters: Federer vs Safin; Roddick vs Hewitt.
The United States swept past Belarus on Saturday to clinch their first Davis Cup final appearance since 1997.
The ace Indian doubles pair beat Andy Roddick and Mardy Fish in their opening match of the men's doubles tennis at the Olympics.
Champion Roger Federer faces Frenchman Sebastien Grosjean for the first time in more than three years today with a place in the Wimbledon final at stake.
Sweden fought back to level their Davis Cup semi-final with United States 1-1 on Friday when Thomas Johansson defeated James Blake for the first time in his career.
Russian Nikolay Davydenko saw off Tommy Haas in the U.S. Open quarter-finals for the second successive year, beating the German 6-3 6-3 6-4 on Wednesday to reach the last four without dropping a set.
Federer's bid to win his first title on the clay courts of the Rome Masters juddered to a premature halt on Wednesday when he lost his second-round clash against Spain's Albert Costa 3-6, 6-3, 6-2.
Novak Djokovic's bid for a record 25th Grand Slam title kicked off on Monday with an easy win over qualifier Radu Albot in the US Open first round.
Andy Roddick, Juan Carlos Ferrero and Roger Federer are in the running for the title at next week's Masters Cup.\n\n
The U.S. took a winning 3-0 lead over Spain in their Davis Cup world group quarter-final tie on Saturday when Bob and Mike Bryan beat Feliciano Lopez and Fernando Verdasco 7-5 6-3 3-6 7-6.
"It was special to win in front of my home fans," Ferrero said after clinching victory in two hours 30 minutes.
Ferrero brushed aside Thailand's Paradorn Srichaphan 6-4 6-2, a result that will be enough to keep him on top of the world rankings.
Agassi polished off former world number one Yevgeny Kafelnikov 6-3, 7-6, 6-4 to reach the U.S. Open fourth round.
The American was beaten by world number 103 Ivo Karlovic of Croatia in the second round.
Tomas Berdych beat James Blake after Andy Roddick had give the US a 1-0 lead.
The Briton swept past Fernando Gonzalez of Chile 6-3, 6-4 to win the $600,000 Washington Classic.
Federer became the first man from Switzerland to reach a Grand Slam semi-final since Marc Rosset at the French Open in 1996.
Britain's Greg Rusedski turned the Wimbledon air blue with a furious outburst of foul language during his 7-6, 7-6, 7-5 loss to Andy Roddick.
American Andy Roddick and Briton Greg Rusedski will be going head-to-head on Centre Court in the race to hit the world's first 150 miles per hour (241.4 kph) serve.
The 32-year-old continued the form that has brought him 22 victories in 23 matches this year, to reach the final of the U.S. Clay Court Championships on Saturday.
Substitute Dmitry Tursunov beat Andy Roddick in an epic five-set battle to seal a Russian victory over the United States.
Roger Federer will end the year as world number one for the third time in a row.