The US Open, tennis' fourth of four grand slams of the year, begins August 31st in New York City.
After beating both Lleyton Hewitt of Australia and Andy Murray of Britain and Scotland in earlier rounds of the Western & Southern Financial Group Masters, Federer yesterday defeated the 4th seeded Novak Djokovic of Serbia 6-1, 7-5 in the championship final.
Federer, who has won the US Open the last five years, will enter next week's grand slam as the favorite as the former world number one Rafael Nadal of Spain has yet to return to the form he showcased before a knee injury.
In women's action Sunday at the Roger's Cup, Dementieva, who has throughout her career experienced serving problems, defeated the former world number one Maria Sharapova of Russia 6-4, 6-3.
Sharapova served up several doublefaults as her own serve failed her at key moments.
Saturday in the semifinals, Dementieva had outlasted an error-prone Serena Williams of the USA 7-6(7-2), 6-1.
In her best US Open result, Dementieva reached the finals in 2002 and 2005.
The Russian, took Gold in singles play at the 2008 Summer Olympics, beating the current world number one Dinara Safina also of Russia in the championship final, before losing in the US Open semifinals 6-4, 6-4 to last year's New York finalist Jelena Jankovic of Serbia.