Michael Phelps won the 100m backstroke at the Austin Grand Prix on Saturday, but the 14-time Olympic gold medallist said his winning time showed he has plenty of work to do.

Phelps triumphed in 54.14 seconds, more than a second slower than his personal best.

“It wasn’t too bad,” said Phelps, who shot to global swimming stardom with his eight gold medals at the Beijing Olympics.

“I would really like to work on being able to finish a race better. My legs were in a lot of pain. That’s just lack of being in shape. I would like to feel a lot less (fatigue) than what I am, just because it’s close to the world championships and we’re heading into an Olympic trial year.”

At least Phelps had the satisfaction of beating compatriot Ryan Lochte – the world’s dominant swimmer in 2010.

After finishing runner-up to Phelps in the 100m fly on Friday, Lochte settled for third in the 100m back behind American Nick Thoman.

As expected, Phelps opted out of the consolation final of the 200m breaststroke – a stroke he rarely swims in competition.

Rising star Missy Franklin, 15, claimed two victories on Saturday, in the 50m free and 100m backstroke.

She won the women’s back in a personal-best of 59.75 seconds.

“I did not think I would go under a minute at all,” Franklin said. “I’m so excited about it. Before the race my coach offered to buy me dinner for (breaking a minute). I should take him to somewhere expensive, shouldn’t I?”