Summer McIntosh, the 18-year-old Canadian swimming star, rolled to victory Sunday in the women’s 400-meter individual medley, setting a world-championship record and winning her fourth individual gold medal of the event.

Summer McIntosh won her fourth gold medal of the World Aquatics Championships in Singapore with a dominant performance in the 400-meter individual medley.

The U.S. men claimed one gold medal over the eight-day meet (Luca Urlando, 200m butterfly), their fewest at a world championships. For the second time, the U.S. won none of the three men's relays (2001).