INDIANAPOLIS, Indiana — Four-time Olympic gold medalist Missy Franklin cruised to victory in the 100m freestyle win at the US national trials in Indiana Tuesday, booking her spot at the upcoming World Championships in Barcelona. Franklin, who won four golds at the London Games last year, was the star attraction on the opening night of the event, which serves as the US trials for the July 19-August 4 World Championships. The 18-year-old set a personal best, and championship record, time of 53.43 to win her race. “Coming home, (my coach) Todd (Schmitz) told me to look at the field coming off the 50 wall and just put my head down and swim it my own way,” Franklin told reporters. “That's what I did.” The championships are the first for the sport without the legendary Michael Phelps since 1998. Phelps, the winner of six medals (four gold, two silver) at the 2012 London Games, retired last year as the most decorated Olympian of all-time. Nathan Adrian, the Olympic men's 100 freestyle champ, repeated as the national champion in that event by finishing ahead of Jimmy Feigen in 48.10. Fourth in the race was Ryan Lochte, the winner of five medals in London. The event was the first for Lochte — the 2012 Olympic 400-meter individual medley champ — at this year's national meet. Another Olympic gold medalist who scored a win Tuesday was 16-year-old Katie Ledecky. Ledecky, first in the women's 800-meter freestyle at London, claimed the event here Tuesday in 8:22.41 Thomas Luchsinger pulled off an upset with a first-place finish in the men's 200-meter butterfly. Luchsinger was first in 1:55.57, ahead of Tyler Clary, who was fifth in the 200 fly at last year's Olympics. Luchsinger stroked to an early lead and withstood a late charge by Clary, whose time was 1:56.58. Cammile Adams won the women's 200 butterfly in 2:08.10. Adams took fifth in the event at the 2012 Olympics. Connor Jaeger finished first in the men's 1500 freestyle. The winning time for Jaeger, last year's Olympic sixth-placer, was 14:53.34. Caeleb Dressel lowered his own American junior record in the 100m free. The 16-year-old Dressel finished eighth with a time of 49.50. — Agencies