Dana Vollmer took a brace of victories at the Santa Clara International Grand Prix, on 54.38 in the 100m free followed by 57.03 in the 100m butterfly, Cal team-mate Natalie Coughlin second in both events, on 54.77 and 58.44.

Vollmer, coached by Teri McKeever, had set a meet record of 57.07 in morning heats. Her day's work marked further seasonal progress for the 100m butterfly world champion, who has notched up six swims between 57.03 and 58.02 so far this year. By this time last year, she had entered that range three times on her way to Shanghai, her best a 57.50.

In the freestyle final, Brittany Elmsie, of Queensland and Australia, challenged the Americans on the way home, producing the only sub 28sec return in the race, 27.94, for a 54.89 third place.

The meet, the final stop of the 2011-2012 USA Swimming Grand Prix Series, runs through Sunday, June 3, witnessed a second brace of gold, Korea's 400m free Olympic champion Park Tae Hwan, coached by Michael Bohl Down Under, leaving the sprint crew for dead over the last 25m on his way to a 48.85 win in the 100m free ahead of 2001 world champion comeback trailer Anthony Ervin, 49.95. No others broke 50.

Like lightining, Park struck twice, in 3:44.96 over 400m freestyle, Australia’s Ryan Napoleon second in 3:49.79, Canada's Ryan Cochrane third 3:50.56.

Australia’s Bronte Barratt was a peg up on the rest in the women's 400m free, her 4:06:13 keeping tab bay Chelsea Chenault, inside 4:09 for the second time on the day with a 4:08.95, that getting the better of the winner's touring teammate Kylie Palmer, on 4:09.79.

California-based Japanese legend Kosuke Kitajima clocked 2:13.24 to win the 200m breaststroke, Scott Weltz on 2:14.27, Christian Schurr Voigt, until now noted as "USA" on rankings but listed by USA Swimming as representing Mexico, third in 2:14.35.

Teammates of the breaststroke Olympic champion but Japanese visitors at Santa Clara, Takuro Fuji, 52.79, and Takeshi Matsuda, 52.84 gave the Rising Sun a lift with a 1-2 finish in the 100m butterfly ahead of Tom Shields, on 53.02.

Caitlin Leverenz, of Cal, had the company of Kaitlin Freeman in the 200m breaststroke, the race ending 2:26.46 to 2:27.83.