Willams, Baltacha, Ivanovic through

Former champion Serena Williams survived a few anxious moments before seeing off the determined challenge of Estonia's Kaia Kanepi at Wimbledon.

Meanwhile, Elena Baltacha showed great tenacity to edge into the second round with a 6-3 2-6 7-5 victory over Angelique Kerber.

And top seed and new world number one Ana Ivanovic cruised into the second round of Wimbledon with a comprehensive 6-1 6-2 Centre Court victory over Paraguay's Rossana De Los Rios.

Williams, the sixth seed, had to save five break points in the opening set before eventually gaining control and sealing a 7-5 6-3 victory on Court One.

The 26-year-old quickly fell 0-40 down on her serve in the first game of the match and had to save a total of four break points before holding serve.

As well as Kanepi had played in the opening set, it was hard to see her coming back from a set down and Williams was quick to establish control in the second.

Elsewhere at Wimbledon, Elena Baltacha's composure frequently deserted her at key moments but she was able to take advantage as her bad-tempered opponent from Germany faded late in the third set.

The British number four from Enfield overcame a nervous start on Court 11 when poor accuracy saw her broken in only the second game.

But she responded magnificently, forcing Kerber - who stands 27 places higher in the world rankings at 131 - to concede service immediately with a powerful forehand.

But then it was the 24-year-old's turn to crumble as she was broken in the third and then saw her service fall apart in the seventh, eventually conceding the set.

She came out firing for the deciding set, however, blasting Kerber into submission.

With her shots alternating from the sublime to the ridiculous, Baltacha could build no momentum and was broken again in the fifth.

Determination alone allowed her to seize Kerber's serve in the eighth and she repeated her heroics in the tenth before securing a match point two games later.

She wasted the chance but, thanks to some dubious line-calls, she claimed a second which was won via a kind bounce off the net.

French Open champion Ana Ivanovic's game was far from flawless but her powerful passing shots still proved far too good for the world number 103, a former top-ranked one junior who has never been past the second round in five attempts.

But it proved a useful workout for Ivanovic, and she showed no obvious ill effects from the right shoulder injury which forced her to withdraw prior to the start of the tournament in Eastbourne last month.

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