Rio Olympics 2016: Swimmer Adam Peaty into final after world record
After a new best in the heats, Peaty qualified for Monday's final (02:53 BST) in the second-fastest time ever.
GB cyclists Chris Froome and Geraint Thomas both missed out on medals in a dramatic men's road race.
But British cyclist Lizzie Armitstead can make amends when she goes in the women's event on day two at 16:15 BST.
She was only cleared to compete 15 days before the Games began after appealing against a ban for missed drugs tests.
American shooter Ginny Thrasher 19 won the first gold of the Games, while two swimming golds helped Australia top the medal table.
There was drama elsewhere with a stray military bullet landing in a media tent and police carrying out a controlled explosion on an unattended bag
near the finish line of the men's cycling road race on Copacabana's sweeping boulevard.