Olympic champion Katie Ledecky has broken her own 800m freestyle world record, while Michael Phelps continued his return to competition.
American Ledecky, 17, took almost three seconds off her old time, clocking eight minutes 11 seconds in Texas.
Compatriot Phelps, 28, took third in the 200m individual medley at the Arena Grand Prix in Arizona.
The 18-time Olympic champion, who retired after the London 2012 Games, clocked 1min 59.76secs.
Phelps, competing in his third meeting since returning in April, led through the first three lengths but could not hold off winner Conor Dwyer and Chase Kalisz on the final freestyle leg.