PERTH, Australia (AFP) — Venus Williams lifted the United States to victory in their Hopman Cup tie against France yesterday.

The USA pairing of Williams and John Isner beat the French team of Jo-Wilfried Tsonga and Mathilde Johansson 2-1 to remain unbeaten in the mixed teams tournament, but only after a remarkable comeback led by Williams when the Americans twice appeared on the brink of defeat.

After Tsonga beat an out-of-form Isner in straight sets, Williams looked down and out when she dropped the first set to Johannson and trailed 4-1 in the second.

The seven-time Grand Slam champion was all at sea against the 87th-ranked Johansson, appearing restricted in her movement and lacking the usual power in her game.

But just when the cause looked lost, the world number 24 climbed off the canvas to win in three sets, 3-6, 7-5, 6-4.

Johansson was breaking the Williams serve almost at will for most of the first two sets, but the American found her service range just in the nick of time and turned the match on its head.

The Americans then claimed the tie with a come-from-behind 6-7 (5/7), 6-2, 10-8 win in a match tiebreak in the deciding mixed doubles, where Williams again lifted them to victory as Isner continued to struggle with his game.

Williams, who has been troubled by injuries and illness in recent years, dismissed any suggestion she was off colour during the match against Johansson.

However, Williams admitted even she thought the match had slipped away.

"I was thinking that if I am going to lose this match, let me at least try to work on my game with the Australian Open coming up," she said of the second set.

"Mathilde is a good player and she was determined to seal the win for her team.

"She was playing well and not making a lot of errors."

The eighth-ranked Tsonga made a perfect start to the new year by demolishing world number 14 Isner in under an hour, 6-3, 6-2.

Tsonga easily blunted the power serving of the lanky American to win in just 55 minutes.

Isner had strapping on his right knee and didn't always appear to be moving totally freely, but later said he only had some lingering soreness in the knee and that it didn't affect his game.

Tsonga, now coached by Australian Roger Rasheed, went into the match with just one win in his four previous clashes with the American.

The Frenchman said he was reaping the early rewards of working hard on improving his mobility during the off-season ahead of the year's first Grand Slam, with the Australian Open starting on January 14.

"I was a bit quicker on court than before," he said.

"It is a good sign for the rest of the competition and Melbourne.

"I was moving well and this makes me a better player."