Englishman Paul Casey was setting the pace but still had work to do as the second round of the Heineken Classic got underway at Royal Melbourne Golf Club.

Casey had the outright lead after a birdie at the final hole on Thursday gave him a seven under par round of 65.

He led from Spain's Santiago Luna on six under.

Sharing third spot a further shot back were England's Warren Bennett and Gary Evans and Australians Peter Fowler and Peter Lonard.

Casey said his bogey five at the 16th - his only blunder - was a mental mistake.

"I was down the left in the rough and I tried to hit a soft nine and made a mistake and batted it into the bunker short - made a good bunker shot and missed the putt," he said.

"Just purely a lack of concentration, it was just disappointing.

"I have had a couple of low ones but I am notorious for throwing in good rounds with bogeys though so I've got to knuckle down and get rid of the errors."

Greg Norman had a one over par round of 73.

Play was interrupted for 90 minutes in the afternoon after a heavy downpour.

Brought to you by AAP © 2024 AAP