Justin Gatlin continues in his preparations for the Rio Games, and was in top form in the Italian capital as he readies for a much anticipated duel with Usain Bolt at the upcoming Olympics.

Justin Gatlin (R) of the United States competes during the men's 100m event at the Rome's Diamond League competition in Rome, Italy, June 2, 2016. Gatlin took the title with a time of 9.93 seconds. (Xinhua/Jin Yu)

Gatlin would be out of the blocks quickly in lane three and held off a late challenge from fellow American Ameer Webb to win the 100-meter in 9.93 seconds, beating his season best by one-one-hundredth of a second. This was his fourth straight 100-meter win, and fifth in Rome, breaking a tie for the meet record with Maurice Greene. Webb and Jimmy Vicaut of France came second and third.

In the women's 800 metres, South Africa's Caster Semenya produced a dominating performance over the final 100 metres but could only match her own world lead time of one minute, 56.64 seconds.

Meanwhile, Almaz Ayana did manage to break her own world lead in the women's five-thousand metres, but her time of 14 minutes, 12.59 seconds wasn't enough to set a new world record. Fellow Ethiopian Tirunesh Dibaba was 1.44 seconds faster when she set the benchmark in June 2008.

In his first Diamond League meet, Great Britain's Greg Rutherford claimed the men's long jump with a season best 8.31 metres on his second attempt.

Valerie Adams of New Zealand threw 19.69 metres on her third attempt to continue a fine run of form with just two months to go until the Rio Olympics.