INDIANAPOLIS – Ian Crocker set a world record in the 50-meter butterfly and the United States avenged an earlier loss to Australia with a victory in the women’s 400 freestyle relay at the Short Course World Championships on Sunday night.

The Americans won two of five finals, giving them 16 victories in 28 events so far. The meet ends Monday.

Crocker, a former Cheverus High of Portland star, touched first in 22.71 seconds, lowering the old mark of 22.74 by Geoff Huegill of Australia at the 2002 championships in Berlin. It was the American’s second gold medal in the 25-meter temporary pool.

Crocker turned and checked the scoreboard, then raised both arms, acknowledging the cheers of 8,421 fans at Conseco Fieldhouse. A female fan held up a hand-lettered sign reading “There’s a croc in the water.”

“I was under water so long, I really couldn’t hear the crowd,” he said. “I botched up the turn a little bit. There are always things you can work on. No race is perfect.”

Crocker, 22, won a gold medal at the Athens Olympics after Michael Phelps gave up his spot in the 400 medley relay final so Crocker could make up for a poor swim in an earlier race. Crocker swam the fly leg and helped the Americans to a world record. Phelps shared the gold, too, after swimming in the preliminaries.

Phelps won the 200 free at this meet before withdrawing Friday because of a back injury.

Crocker dropped out of the 100 fly preliminaries Sunday morning to conserve energy for the record he wanted to set in the evening. The effort was worth $15,000 from FINA, the sport’s international governing body.

“I really wanted to walk away from this meet with a world record,” he said. “I knew and the coaches knew there was a chance for the world record, so why not go get it?”

Crocker won the 100 fly Friday.

Brooke Hanson of Australia won the 100 breaststroke and 200 individual medley, tying the record for most golds at a short course championships with five. American Kaitlin Sandeno won four golds.