Former US Open champion Samantha Stosur became the first major casualty on the opening day at Wimbledon as the Australian suffered a first-round loss.

The 30-year-old was beaten 6-3 6-4 by Belgium's Yanina Wickmayer on Court Three, situated on the site of the old Court Two which became known as the 'graveyard of champions'.

Wickmayer, supported from the stands by countrywoman and four-time grand slam winner Kim Clijsters, whose academy she trains at, clinched her victory with a classy forehand cross-court winner.

For 17th seed Wickmayer, the result was the latest in a long line of Wimbledon disappointments and means that after 12 visits she still has yet to go beyond the third round.

The first winner of this year's championships was Russian 32nd seed Elena Vesnina, who breezed through 6-0 6-4 at the expense of Austrian Patricia Mayr-Achleitner.

Sloane Stephens, the 21-year-old American, was a quarter-finalist at Wimbledon in 2013 but made a first-day exit this time, losing what always looked a tricky opening assignment against Maria Kirilenko.

Russian Kirilenko, who reached the last eight two years ago, prevailed 6-2 7-6 (8/6) on Court 18.

Japanese 43-year-old Kimiko Date-Krumm threatened an upset against an opponent 18 years her junior as she swept ahead against Russian 22nd seed Ekaterina Makarova.

However from 5-0 ahead in the first set Date-Krumm's high standards began to fall and the veteran was beaten 3-6 6-4 7-5.

The eighth seed and two-time Australian Open champion Victoria Azarenka has reached two Wimbledon semi-finals but not yet gone further.

She was troubled in the second set of her first-round match by veteran Croatian Mirjana Lucic-Baroni, who built a 5-3 lead, but Azarenka turned it around to prevail 6-3 7-5.

Venus Williams ended her three-year wait for a Wimbledon victory courtesy of a 6-4 4-6 6-2 win over  Spanish clay-courter Maria-Teresa Torro-Flor.

The 34-year-old, who like Serena is a five-time former singles champion, is that she is playing by her own rules, ready to tackle any challenge that comes her way.

Chinese second seed Li Na was a 7-5 6-2 victor against Poland's Paula Kania.