KAZAN, Russia — Ask Katie Ledecky to name what she believes is the most amazing athletic feat in her lifetime, and she will talk about Michael Phelps’s eight-gold-medal performance at the 2008 Beijing Olympics, helped along by the anchor leg that Jason Lezak unleashed in the 4x100-meter freestyle relay to deliver Phelps his second gold.

“I remember watching and cheering really loudly,” Ledecky said.

At this year’s world championships, Ledecky’s teammates watched video of Lezak reeling in his French counterpart to get motivated for their own races. But that was before Ledecky gave them another chain of indelible images to latch on to for inspiration.

Ledecky capped off a history-making week on Saturday at Kazan Arena with another milestone. In the 800-meter freestyle, the event that launched Ledecky into the international spotlight at the 2012 London Olympics, she set her 10th world record of the past 24 months with a clocking of 8 minutes 7.39 seconds. The time was 3.61 seconds better than her 13-month-old mark.

Ledecky, 18, slapped the water three times — once for each individual world record she set at these world championships.