Barcelona - Russian Nikolay Davydenko checked in for another successful work day on the clay Friday while Rafael Nadal took advantage of a quarter-final walkover as the pair prepared for a Saturday semi-final clash at the Barcelona Open.

Top-seeded world number one Nadal put in some practise time after learning the day before that seventh-seeded Argentine opponent David Nalbandian would not be fronting up for their match due to hip problems which intensified during the previous round.

Miami  - Russians Maria Sharapova and Nikolay Davydenko both withdrew on Friday from next week's Miami Masters with injuries as the American hard court season moves to its second major event of the month.

Sharapova, who underwent shoulder surgery last October, tried and failed to test her shoulder with doubles last week at Indian Wells, California, losing in the first round with partner Elena Vesnina.

Her return to the WTA now looks to be put back to Rome on clay in May.

Melbourne  - The Australian Open has lost injured world number five Nikolay Davydenko as the Russian withdrew due to a nagging heel injury.

The opening Grand Slam of the season suffered its first high- profile defection through the pullout. Also on the possible danger list are Maria Sharapova and world number two Serena Williams.

Neither have played for months - Sharapova has missed six months - but both insist they will be ready for the major, which begins in 11 days.

Shanghai - Nikolay Davydenko had to overcome a late struggle from Jo-Wilfried Tsonga before defeating the Frenchman 6-7 (6-8), 6-4, 7-6 (7-0) to start with a tight victory at the Masters Cup on Sunday.

The Russian had to sweep a third-set tiebreaker after failing to serve out victory leading 5-3 in the third, scratching through in two hours, 43 minutes.

Novak Djokovic broke his duck at the year-end spectacular, winning his first career match at the event after three 2007 losses.

The Serb overpowered Argentine Juan Del Potro 7-5, 6-3 to take the early lead in the Gold group.