"He just needs to continue to get better. It's been great so far. We are both 23, so hopefully we are going to do this for a lot of years," Murphy added.

Team China, meanwhile, is targeting an improvement in relay races as it bids to challenge the overall dominance of the US.

At the Hangzhou worlds, Wang Jianjiahe, Li Bingjie, Yan Junxuan and Zhang Yuhan won the host's only relay title in the women's 4x200 free, with the US claiming nine of the 12 relay golds up for grabs.

"Random results in individual events do not represent consistent power in the sport if measured against world leader the US," said team manager Cheng.

"We will focus more on improving our relay teams to try to close the gap.