American swimming prodigy Katie Ledecky took the headlines at Friday's action at the Arena Pro Swim Series, matching Michael Phelps' 400m freestyle time.
The most decorated Olympian of all time, Phelps has used the meet in Arizona as his comeback from a six-month ban after a drink-driving arrest.
He started well with a 100m butterfly win over Ryan Lochte on Thursday, but Friday's action saw is progress checked.
Phelps failed to make it out of his 400m freestyle heat after clocking four minutes, 2.67 seconds - only good enough for the 'C' final, which he opted not to compete in.
Ledecky - still a high-school student, though already an Olympic gold medalist in the 800m freestyle - turned heads as she matched the time set by Phelps.
In truth, Phelps had not been expected to make a splash in an event he had not competed in for six years, though Ledecky's achievement is nevertheless seen as further proof of her burgeoning talent ahead of this year's World Championships in Kazan and the Rio Games in 2016.