Stuttgart  - Russian seeds Svetlana Kuznetsova and Nadia Petrova posted hard-fought three-set victories on Wednesday to reach the second round of the Porsche Grand Prix.

The fifth-seeded Kuznetsova needed five match points to defeat German qualifier Andrea Petovic 6-4, 5-7, 6-1 in 2 hours 6 minutes.

Petrova, the sixth-seeded 2006 champion and 2008 runner-up, was on court 20 minutes longer in her victory against Zheng Jie of China 6- 4, 5-7, 6-4.

Stuttgart - Dinara Safina clobbered Sara Errani 6-0, 6-1 in her first match as world number one tennis player on Tuesday night for a place in the second round of the Porsche Grand Prix. Safina took just 51 minutes to win the lopsided contest, clinching victory with an ace against the 37th-ranked Errani.

Safina, who turned 23 on Monday, dethroned Serena Williams at the top of the rankings last week. It was also her first match on clay of the season.

Stuttgart - Jelena Jankovic hopes to return to the top of the women's tennis rankings now that she has regained her form at the start of the clay court season. The Serbian claimed the top spot in late 2008 but has slumped to a current number three with no title yet in 2009.

Jankovic on Tuesday attributed the slide to too much fitness training and personal problems in the off-season which made her slow and sluggish on the court.

Stuttgart - The pink birthday cake came at the right time as Dinara Safina likes to award herself with some unhealthy food for good things she has achieved.

Turning 23 on Monday, the Russian said that "I like to give something to myself" and to "celebrate every time when the opportunity is there."

The birthday was one occasion, but Safina is also playing her first tennis tournament this week at the Porsche Grand Prix since taking the world number one ranking right days ago.

Stuttgart - Doubt was raised about Mercedes' future in Formula One racing by a supervisory board member said ahead of Sunday's Bahrain Grand Prix.

"Formula One is not accepted among the employees. One has to take notice of that," Helmut Lense, a works council chairman and board member of Mercedes' parent Daimler, told Thursday's edition of the Stuttgarter Zeitung daily.

Lense said that recent workforce meetings at Daimler plants revealed the negative attitude towards the expensive sport and added that Mercedes should pull out of F1.

Stuttgart - Hero Group, the Indian industrial conglomerate controlled by the Munjal family, has abandoned a project to jointly assemble Mercedes-Benz trucks with Daimler of Germany in Chennai, Daimler said Wednesday.

Left with 100 per cent of the project, Daimler said it would press ahead anyway.