QINGDAO-- After posting a season's best time in the 100m backstroke at the Chinese national championships, world champion Xu Jiayu said here on Tuesday that he expected to show his best and set the world record at the 2019 FINA World Swimming Championships in Gwangju, South Korea in July.

Xu was in a class of his own, winning in 52.27 seconds to defend his 100m backstroke title in what was his second fastest time ever. Li Guangyuan was runner-up with 53.99 and Wang Guanbin finished third in 54.64.

"Physically I felt not in my best shape but it was a challenge for me. I just performed my normal form. I want to show my best at the World Championships," Xu said.

Xu, world champion in 2017, was 0.01 shy of the world record set by Olympic champion Ryan Murphy of the United States.

"Everyone asked me the same question: when will you break the world record? It is my dream to break the world record and I was very close to that. But it is not the right place and right time to do that here since I am not ready," said Xu, who shattered the short course world record in the 100m backstroke last November.

"I expect to show my best at the World Championships and the Olympic Games. But it is not easy to break the world record. I am not in a hurry and I need to improve myself in many ways."

Xu finished second in the 100m backstroke at the FINA World Championships 25m in Hangzhou last December, 0.03 seconds behind champion Murphy.

"It was a pity that I did not live up to expectations by winning a gold medal in home water. I was too eager to show off. It was a lesson that I should be more patient and confident in myself. I am waiting to hit my next peak in Gwangju," said Xu, who will also compete in the 50m and 200m backstroke at the Chinese qualification meet for the World Championships.