Having won individual 10m platform gold as a 15-year-old in 2009, Daley is now the first British diver to win multiple World Championship medals.
The mixed format sees one male and one female diver perform individually from both the three-metre springboard and 10m platform.
“We really don’t know what happened there,” said Daley, who will compete in his main platform event on Saturday. “We went in to the competition as a bit of a warm-up for our individual events.
“To come away with a results like that is amazing. I had my highest score ever on the armstand, Becky did one of her best front dives in a competition she’s ever done.”