The clash of some of the world's greatest sprinters, notably Britain's Mark Cavendish and Germany's Andre Greipel, may upstage Lance Armstrong's farewell race outside the United States.

The Tour Down Under cycle race begins in earnest on Tuesday and the first event of the UCI World Tour favors sprinters.

Greipel won it two of the last three years. This year's event has attracted many of the world's top 10 sprinters.

Cavendish and Greipel had a reportedly fractious relationship while teammates at Team HTC-HighRoad. Cavendish will ride for the U.S. Highroad team in Australia and Greipel rides for Belgium-based Team Omega Pharma-Lotto.

The 133-strong field for the six-day tour also includes several top sprinters. The United States' Tyler Farrar (Team Garmin-Cervelo), New Zealand's Greg Henderson, Italy's Francesco Chicchi and Germany's Gerald Ciolek all are there.

Australians Allan Davis, a former tour winner, and Robbie McEwen ride for Armstrong's Team Radio Shack.

The rivalry of Cavendish and Greipel will be most closely watched, though both have attempted to play down reports of friction. Cavendish ridiculed claims of acrimony as a media construction.

"I just want to be near him," Cavendish said jokingly when asked about his relationship with Greipel. "If you don't know, we're actually lovers. You wanted your headline with me and Greipel, you've got it."

Greipel denied harboring any ill will toward Cavendish.

"I was always loyal to Mark," Greipel said. "Hopefully he was also respectful to me.

"I have a respect for all the riders, that's how I am.

"I think it's not always Mark Cavendish who is my main rival, there's other riders. I just look forward to being competitive like the other years. And I respect him of course. But the other way, I don't know, you have to ask him."

Greipel and Cavendish's bids for success in Australia will depend on the abilities of their teammates to put them in stage-winning positions. Cavendish has his regular lead-out man, Australian Mark Renshaw, in his team which suggests he will be well-placed in the tour traditional bunched sprint finishes. Renshaw showed promising form when he finished second behind teammate Matthew Goss in the 32-mile criterium prologue to the tour on Sunday.

Greipel has also assembled a team capable of leading him to stage wins.

"I brought three guys from HTC (Adam Hansen, Vicente Reynes and Marcel Sieberg). They know how I want them and they will set me up for sprints," he said.

"And yeah, we have a lot of experience. Of course we want to perform and it's always good to start your season with some success."

Tuesday's first stage begins in the northern Adelaide suburb of Mawson Lakes and takes the riders 90 miles through the Barossa Valley wine-growing region of South Australia to the village of Angaston where the sprinters will clash for the first time.