Michael Phelps tuned up for his last Olympics in emphatic style on Sunday. He qualified for a fifth individual event on the next-to-last night of competition at the U.S. Swimming Trials.

The 14-time Olympic gold medallist still showed showing no signs of wearing-down after a draining week of high-pressure swimming. He powered home over the last lap to win the 100 metres butterfly final in 51.14 seconds.

It was the 27-year-old's fourth straight win of the trials, after finishing second to Ryan Lochte in the 400m medley final on Monday. The result ensured he would contest his expected eight-event schedule in London, with the addition of the three relays.

Lochte sliced half a second off his personal best time to finish third in the 100m butterfly, which he usually does not swim, but missed out on another Olympics race with only the top two qualifying out of the event. Lochte's rivalry with Phelps promises to be one of the highlights at the Games. He's already qualified in four individual events, plus at least one relay on the road to London.

Michael Phelps, 14-time Olympic Champion, said, "I think the only thing that's different in my eyes, really, is this is my last one on American soil, my last Olympic Trials swim. That's it. It's kind of weird. Bob and I, when we walked into the pool, we said this was our last Olympic Trials swim, and it's crazy to think about 12 years ago I made my first team."

Ryan Lochte, 6-time Olympic Medalist, said, "You know what? This meet, I wanted to come into this meet knowing that I was a little tired, that I wasn't fully rested. So I'm not fully rested right now. I'm getting better as the days go on. So I know that come London, I'm going to be a lot more rested and I'm going to be a lot better."