OSAKA: Justin Gatlin pipped Japan's Yoshihide Kiryu to win the men's 100 metres as fellow American Michael Norman fired a world championship warning with a superb 200m at the Golden Grand Prix Osaka on Sunday.

The 37-year-old Gatlin produced a strong finish to clock 10 seconds flat, the reigning world champion dipping at the line to edge out Kiryu by a hundredth of a second at the IAAF world challenge meet in Osaka.

Indonesia's world under-20 champion Lalu Muhammad Zohri broke his own national record as he took third in 10.03 -- the fastest time ever recorded by an athlete from Southeast Asia.

While Gatlin targets one last hurrah at the world championships in Doha later this year, Norman laid down a marker by winning the men's 200m in a meet record 19.84 seconds, shaving 0.03 off the mark Namibia's Frankie Fredericks set 20 years ago.

The runaway victor, who last month clocked a personal best of 43.45 in the 400m, left Yang Chun-Han trailing in his wake, the Taiwanese runner-up in 20.50.

Ominously for his rivals, Norman insisted that he can still get faster.

"I feel as though there are multiple areas I can improve on," said the 21-year-old.

"I didn't feel as though the intensity that I usually have during a 200m was there."

Meanwhile, the Japanese men's 4x100m relay quartet made amends after their disqualification at last week's World Relays in Yokohama by beating Team USA into second place.

Clips of Kiryu fumbling and then catching the baton in mid-air went viral, but the Japanese -- shock Rio Olympic silver medallists behind Usain Bolt's Jamaica -- made no mistake this time as Kiryu anchored them home in a world-leading 38.00 seconds.

The Americans, who had Gatlin on their second leg, took silver in 38.73.