Cameron Smith has set himself up for a head-to-head duel with former world No. 1 Brooks Koepka at the lucrative World Golf Championship event in Florida.

Meanwhile Greg Chalmers and Cameron Percy are both in contention at the PGA Tour tournament in Puerto Rico as Australians find themselves to the fore.

Smith shot a second-round 66 with seven birdies to go with his opening 68 and he sits tied-second in the WGC Workday Championship at Concession near Tampa in Florida at 10 under par.

The Queenslander is a shot behind Koepka, who also shot 66 today, and was delighted with his play having finished fourth at Riviera last week. “This is probably the best my ball striking's felt to myself in a very long time,” he said after his round.

Smith had a quiet period after he won his first individual US Tour event last January in Hawaii, a fact he puts down to complacency.

“Probably just got a little bit content there, thought everything was good. It was still decent, but it definitely wasn't my best stuff. The last few weeks I feel like I've probably done more practice in the last two weeks than I have the last year. Just goes to show what a little bit of hard work can do.”

Fortunately, that is all behind him as he chases a nice share of the $US9 million prize pool.

Smith is in the final group with the resurgent Koepka tomorrow. He leads the cluster of Australians easily, with Jason Day at four under par the best of the rest, just inside the top 20.

Meanwhile at Grand Reserve Golf Club in Puerto Rico, veteran Chalmers shot a second-round 68 after an opening 66 to sit outright second, a shot from the lead as he seeks his first main tour win since 2016.

Percy, another veteran who is having a consistent year, shot a 69 to sit tied-fifth overall.

WGC leaderboard

Puerto Rico Open leaderboard