Shane Watson scored an unbeaten century before lunch against Worcestershire as Darren Lehmann's first selection call as Australia coach paid immediate dividends.

Lehmann confirmed before his side's final Ashes warm-up that Watson and Chris Rogers would form a new opening partnership in the first Test against England on July 10.

And the pair enjoyed their first outing together, Watson reaching lunch on 102 not out and Rogers making a more circumspect 43no as they added 150 for nought at the interval.

Quite how much Australia can read into the stand is questionable given the modest nature of the Worcestershire attack operating without leading wicket-taker Alan Richardson, but Lehmann will be delighted with the pair's application.

Watson was particularly dominant, punching the first ball of the day for four and adding 13 more boundaries as he hit powerfully to all parts of the ground.

There were also two sixes as he reached a first-class hundred for the first time since October 2010.

Michael Clarke had opted to bat first having won the toss and Watson wasted no time in reassuring him it was the right decision.

Chris Russell's first ball of the day was a wide half-volley and Watson happily punched it to the boundary.

Debutant Charles Morris started with a maiden to Rogers but that was a rare win for the bowlers as the Australia openers shared four boundaries in the space of 11 deliveries.

Watson was hitting the more powerful strokes but Rogers brought up the team fifty with a lovely back foot drive off Morris before whipping his fourth boundary through mid-wicket two balls later.

Watson gave a half-chance when he hoisted Gareth Andrew into the onside, but Nick Compton - guesting for Worcestershire in a bid to press his England claims - could not pluck a high catch and it went for six.

His half-century came up in 49 balls and he took the score into three figures when he lifted Jack Shantry for a big straight six.

Rogers almost played Russell on for 30 but otherwise the progress was serene.

Watson plundered Russell for three boundaries in five balls as he continued to assert himself and moved brought up his ton when he nudged Morris off his pads.