It was the one thing missing from her career, and now she has it. Serena Williams was the deserving winner of the women's singles gold medal at London 2012 after crushing Maria Sharapova 6-0 6-1 in the final.

It was the most one-sided women's final in Olympic history, and the perfect end for the five-time Wimbledon champion to a tournament where she established herself as the clear favourite from early on after some dominant performances on the grass she loves so much.

As owner of a singles gold medal and all four Grand Slam titles, Williams has captured the coveted singles Golden Slam, becoming only the second woman after Steffi Graf to achieve the feat. Graf claimed the Golden Slam in a single calendar year in 1988 when she took the gold medal in Seoul. She also joins sister Venus as an Olympic champion, Venus taking gold 12 years ago in Sydney.

The American said afterwards it was probably her best performance in any tournament. "This one is so high up there, being Olympic gold champion, being Golden Slam champion singles and doubles, that's pretty awesome." Williams achieved the doubles Golden Slam in Beijing.

"I would have been happy whether I would have got a silver or gold. It's such a great achievement to get on that medal stand," she continued. "So that was awesome. But obviously I wanted gold. Now Venus and I both have gold singles, so it's pretty cool."

Williams lost just 17 games and no sets on her way to the title, and dropped her serve just once. Although she had an 8-2 head-to-head advantage over Sharapova going into the final, this was her easiest victory over the world No. 3. And it wasn't as if she had it easy in terms of opponents before the gold medal match: Williams crushed world No. 1 Victoria Azarenka 6-1 6-2 in the semis, and in earlier rounds defeated former world No. 1s Jelena Jankovic and Caroline Wozniacki, and Beijing bronze medallist Vera Zvonareva.

The American's rout of Sharapova eclipsed the previous easiest victory in a women's singles final at the Olympics, enjoyed by Suzanne Lenglen of France when she beat Great Britain's Dorothy Holman 6-3 6-0 in 1920. Although it was a hugely disappointing result for the Russian, she wins the silver medal in her first Olympic Games.

"She's playing incredibly confident tennis, Sharapova said of Williams. "After winning Wimbledon, you've seen her level progress so much here over this tournament. With every match she's played, she's playing better, hitting harder, so much power on the ball. Even against the wind today, her shots were very powerful. Yeah, I mean, she's done an incredible job of keeping that up."

Williams broke Sharapova to love in the second game of the match and the stunned crowd looked on as she broke again two games later. On a breezy day, Sharapova was clearly having trouble with her serve, and struggling to get her first serves in. Sharapova could only manage a point on the Williams' serve in the next game, and before she knew it she was serving, 0-5 down, to stay in the set.

The Russian managed to move up a gear to get to 40-0 up before being pegged back to deuce by some excellent returning from Williams. Sharapova moved to advantage with a rare trip to the net, playing a volley followed by a smash, but then she double-faulted for the score to return to deuce and Williams got another break point. Sharapova tried the volley again, but this time the American replied in kind to take the first set in half an hour.

With Sharapova getting no opportunities on the American's serve, Williams hit a forehand winner to break again in the second game of the second set as cries of 'C'mon Maria' around Centre Court did little to drag the Roland Garros champion out of the trough she was in. The Russian seemed overwhelmed by the barrage on the other side of the net as Williams cruised to a 3-0 lead.

"I was so focused here," Williams said to explain her superb performance. "I remember I was serving and I was thinking, Serena, this is your best chance to win a gold medal. You played Wimbledon on grass. You played great on grass. Pull it together. I was thinking, I got to do this."

To a huge cheer around the stadium, Sharapova held serve in the fourth game, and raised her level in the next game to fight her way to two break points. The first came with a bit of help from a Williams double fault and the American saved it with a forehand winner; the Russian got the second when Williams sent a forehand into the net but the result was the same as she fought her way clear.

That game provided a glimmer of hope for the luckless Roland Garros champion but it was too little too late, and she couldn't prevent Williams from breaking her again in the next game to lead 5-1. Williams followed up by serving for the match, winning the last two points with aces to take her ace count for the tournament to a staggering 60.

"Obviously there's things that I could have done different, but she was just too quick and too powerful today," said Sharapova.

As Williams jumped up and down with sheer joy her sister Venus was in the stands to share the moment with her. Serena now joins her older sibling as winner of three Olympic gold medals, having collected the doubles gold with Venus in Athens and Beijing.

Serena and Venus are still in the women's doubles event in London - they play their semifinal today and both women now have the chance to become the first players to win four Olympic gold medals.