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.

McIntosh is aiming to win five gold medals in individual events at the worlds in Singapore, and the first one came Sunday in the 400-meter freestyle on the first of eight days in the pool. Only legendary American Michael Phelps has ever won five individual medals in the worlds. He also did it at the Olympics.