Sly Simon Gerrans' dash on day one sets up a classic Santos Tour Down Under

THE three biggest threats to Simon Gerrans defending the TDU title are predicting an intense few days and a barrage of attacks.

THE three biggest threats to Simon Gerrans defending the Tour Down Under's ochre jersey all the way to the finish are predicting an intense few days and a barrage of attacks as they try to claw back lost time.

Rohan Dennis, Richie Porte and Cadel Evans may be forced to attack Gerrans earlier than the traditional Willunga showdown on Saturday after the national champion put himself in the box seat for a third TDU crown with an 11-second lead over his main rivals on Tuesday.

Dennis said his team would begin planning how to unhinge Gerrans - if that's at all possible - starting from today on an undulating course around Stirling then the Corkscrew Road climb on Thursday.

"It's (aggression) going to have to come earlier, he's (Gerrans) got some super form so it's not going to be easy to get rid of him on any stage and if he's beating Greipel in a sprint he's got some speed as well," Dennis said.

"He's definitely the favourite and it's going to be tough, so we have to think about ways to bring him unstuck.

"It's (11-second lead) quite costly and it is a bit of a concern but there are still other stages to go, there are going to be big time gaps on Stage 3 and Willunga is going to be a fight to the finish.

"I don't want him (Gerrans) to have a bad day, but I want to have a super day and hopefully have a real crack there and get some time back."

Evans (9th) avoided the crash in the final few kilometres, which saw Belkin's David Tanner suffer a suspected broken collarbone, and finished with Gerrans' front group to trail by 11 seconds.

But Porte (29th) and Dennis (63rd) were both held up by the spill and lost further time to be 15secs in arrears.

Team Sky's Porte said there was no need to panic and it was a long way to the finish in the Adelaide CBD on Sunday.

"As long as he (Gerrans) doesn't win three stages it's going to come down to Willunga anyhow," Porte said.

"I guess it's good for him that he can sprint but (it was the) first day and now they've (Orica-GreenEDGE) got to chase tomorrow (Thursday) and ride on the front and that's good for us.

"(Wednesday) is a hard stage but Corkscrew (Thursday) I think is probably going to be the first day we really see fireworks."

Porte said it was at times stressful going into the climb up Menglers Hill 12km from the finish but his team did a super job.

"Our team was first into the climb and the guys were absolutely brilliant, we were lucky to get through without crashing because we came very close there but we all survived."

BMC Racing Team's Evans admitted it wasn't the perfect start for him but said it was merely the first day of what he expects to be a "pretty intense week of racing".

Gerrans signalled his intent early yesterday when he leapt from the bunch to take a one-second time bonus on an intermediate sprint, then had enough in the tank to beat German star Andre Greipel in the finish.

The TDU continues with Stage 2 from Prospect to Stirling on Wednesday.