Wimbledon PHOTOS: Serena, Djokovic start with easy wins, Robson stuns Kirilenko

Serena Williams began the defence of her Wimbledon title with a comfortable 6-1, 6-3 victory over Luxembourg's Mandy Minella to stretch her unbeaten run to 32 matches.

The world number one, playing her first match since winning the French Open, scorched through the first set in 19 minutes, but was given a brief fright at the start of the second when she lost her serve to go 2-0 down.

The 16-times Grand Slam winner swiftly regained control, however, breaking in the very next game, before romping away with the match.

Top seed Novak Djokovic proved rock solid as he cruised past Germany's Florian Mayer 6-3, 7-5, 6-4 to reach the second round.

The Serb broke 34th-ranked Mayer's opening service game and never looked troubled on Centre Court, wrapping up victory by swiping away a winning forehand.

Djokovic was back in action for the first time since losing a semi-final epic against Rafa Nadal at the French Open and looked sharp on the lush grass.

Former French Open champion Li Na had a short and sweet ride into the second round of Wimbledon on Tuesday, spoiling Dutchwoman Michaella Krajicek's comeback to the tournament with a 6-1, 6-1 victory.

Li's progress was so straightforward that she began to lose concentration after going 5-0 up in the second set, allowing Krajicek to hold and then save two matchpoints in a long seventh game on a sunny Court 12.

The sixth-seeded Li, China's first Grand Slam champion when she won the 2011 French Open, recovered and hit a winning serve on the third matchpoint to progress to a meeting with either Simona Halep of Romania or Olga Govortsova of Belarus.

Krajicek, 24, had not played at Wimbledon since 2008, although the family name is still on the honours board after brother Richard won the men's singles title in 1996.

When Kimiko Date-Krumm first retired from tennis in 1996, her first-round opponent at this year's Wimbledon was one year old.

On Tuesday, the diminutive Japanese player made light of the longevity statistics, sailing through to the next round by beating Germany's Carina Witthoeft 6-0, 6-2.

"I have a lot of passion. I like challenge because it is not easy for my age," said the 42-year-old who took a 12-year break from the sport but missed it too much and just had to come back.

For her, tennis is not just a power game. Winning is all about mental agility. That way you can outfox younger opponents.

"We need experience. That's why it's not anymore only younger players who can go to the top level," she said.

She quit at the end of 1996 but after a 12-year gap in which she met and married German racing car driver Michael Krumm, Date-Krumm returned to the sport.

She never thought she would miss the global grind of the tour. "But I love sport, I love tennis. And I was working for TV so I came here for many years doing TV commentary." she said.

The tennis bug bit her all over again.

"I thought how beautiful tennis is as a sport. Then little bits started changing my mind," she added. "When I came back, I was enjoying it very much, even when I'm losing."

It is not just chateau-bottled wine that improves with age. Date-Krumm has stopped putting pressure on herself. Now she is out there enjoying matches, win or lose. Jaded is not an adjective you would ever use to describe her play today.

In January, she turned back the clock to become the oldest woman to win at the Australian Open. In Paris, she may have won only two games in the French Open against Australian Sam Stosur but she still raised her arms in celebration.

Martina Navratilova holds the record for being the oldest winner of a grand slam match in 2004 at the ripe old age of 47 years and 248 days.

Who knows? In another five years, Date-Krumm might be rewriting the record books if she still keeps having so much fun.

Britain's Laura Robson kept the home flag flying in the women's singles when she upset Russia's number 10 seed Maria Kirilenko 6-3 6-4 in the first round at Wimbledon on Tuesday.

The unseeded Robson, 19, moved comfortably through the first set and led 4-1 in the second before Kirilenko got a break back as she tried to stage a recovery against the world number 38.

But the Russian, who reached the quarter-finals at the French Open last month, failed to come to terms with Robson's smooth groundstrokes and could not sustain her momentum.