Monaco: Controversial American Justin Gatlin outsprinted up-and-coming compatriot Noah Lyles in the 100 metres at Friday's Diamond League meet in Monaco where Sifan Hassan set a new world best in the women's mile.

Gatlin kept both his nerve and form after an average start to streak through the finish line in 9.91 seconds, just one-hundredth of a second ahead of Lyles, 21. Hassan came home in 4min 12.33sec, smashing Svetlana Masterkova's previous best by 0.23 sec.