Michael Phelps booked his ticket in the 200m freestyle and 200m butterfly in the World Championships Wednesday after the Olympic champion won in the U.S. trials in Indianapolis.

U.S. swimmer Michael Phelps adjusts his goggles before the start of the men's 200m freestyle final at the USA Swimming National Championships in Indianapolis, Indiana July 8, 2009. [Xinhua/Reuters Photo]

Phelps finished first in 200m free in one minute 44.23 seconds before winning the 200m fly in 1:52.76. Phelps won both events in world record times as part of his eight-gold haul at the Beijing Games.

Aaron Peirsol got a World Championship berth and his world record back in the 100m backstroke with a time of 51.94.

Michael Phelps of the U.S. swims to a win in the men's 200m butterfly final at the USA Swimming National Championships in Indianapolis, Indiana July 8, 2009. [Xinhua/Reuters Photo]

Peirsol, winner of Olympic gold in Athens in 2004 and Beijing, had held the record since 2004 before Spain's Aschwin Wildeboer Faber lowered the mark to 52.38 at the Mediterranean Games on July 1.

Olympic silver medallist Matt Grevers, who led Peirsol by a narrow margin at the turn, settled for second in 53.11.

U.S. swimmer Michael Phelps swims to a win in the Men's 200m Butterfly final at the USA Swimming National Championships in Indianapolis, Indiana, July 8, 2009. [Xinhua/Reuters Photo]

In other races, Dana Vollmer won the women's 200m free in 56.20 ahead of Allison Schmitt (1:57.25), while American record-holder Katie Hoff finished eighth in the event she had reckoned offered her best chance for a trip to Rome.

Hayley McGregory sealed her spot in the world team by winning the 100m backstroke in 1:00.07, ahead of 15-year-old Elizabeth Pelton.

Pelton clocked 1:00.66 to earn her second runner-up finish of the meet after her second-placed finish in the 200m medley on Tuesday.