By Miles Evans

PERTH - Top seeds Russia kept alive their chances of a Hopman Cup triumph by clinching the decisive mixed doubles for a 2-1 victory in their Group A encounter against the United States on Tuesday.

Dmitry Tursunov and Nadia Petrova combined to beat Mardy Fish and Ashley Harkleroad 6-3 7-5 to claim their first win of the mixed team competition after a shock loss to Australia in the tournament opener on Saturday.

Earlier, Petrova swept past Harkleroad 6-3 6-0 in the opening singles before Fish kept the tie alive with an impressive 6-1 6-4 triumph over world number 22 Tursunov.

France play Australia in the day's second Group A match encounter later on Tuesday.

The Americans, who can no longer make Friday's final at the Burswood Dome after also losing their opener to France, were kept in the tie with a fine performance from Fish in the men's singles rubber.

The American world number 47 served superbly to down Tursunov 6-1 6-4 in just 58 minutes.

Fish saved three break points in the third game before rattling through the first set, using powerful strokes on both flanks to undermine the frustrated world number 22.

The crucial break in the second came when a perfect forehand return clipped the baseline to give him a 4-3 lead and he duly served out for the match despite trailing 0-40 in the deciding game, sealing it with his 13th ace.

"I played really well today and I am really excited about that," said Fish, whose ace tally came without a double fault.

"I served great today. For me when I play my best tennis it all starts with my serve. I'm looking forward to the mixed doubles."

Earlier in the day, world number six Petrova gave Russia a 1-0 lead with victory over Harkleroad.

Petrova, shocked in her first match in the mixed team competition by Australia's Alicia Molik on Saturday, used her superior hitting from the back of the court to ease past the world number 86 in 67 minutes.

Petrova clinched the opener on her third set point with a crunching forehand winner and hit the ground running in the second, breaking the American in the first game and wrapping the set up in just 22 minutes.

"I felt a bit more, not confident, but with a match under my belt I felt more comfortable on the court," the 24-year-old said in a courtside interview.

"It's so good to be out here competing, it's completely different to practising and I wanted to start the New Year on a good note."

Petrova, winner of five titles in 2006, clearly shook off the rust that dogged her performance against Molik, against whom she lost in three sets in the tournament's opening match.

"My serve has been much more consistent today, not too many double faults. I felt more confident to try and take the game, put her under pressure in the rallies and force mistakes."