Rio Olympics 2016: Usain Bolt & Justin Gatlin ease through 100m heats
Jamaica's defending champion Usain Bolt made it through the 100m heats without alarm to reach the Olympic semi-finals.
Bolt cruised through in Rio in 10.07 seconds, as American rival Justin Gatlin qualified fastest in 10.01.
Britain's CJ Ujah (10.13) and James Dasaolu (10.18) went through as the eighth and 19th fastest qualifiers, but James Ellington (10.29) is out.
The semi-finals take place on Monday from 01:00 BST, with the final scheduled for 02:25 BST.
"I'm happy to get the first one out, it felt OK," said Bolt. "It wasn't the best start. Hopefully tomorrow I can go much smoother, I'm feeling good, I'm happy.
"Now it's all about execution and getting it right when it comes to the final."
Christine Ohuruogu booked her place in the semi-finals of the women's 400m.
The 32-year-old, champion in Beijing in 2008 and silver medallist in London four years ago, looked smooth as she clocked 51.40 seconds to finish second in her heat to American Natasha Hastings.
British champion Emily Diamond clocked 51.76 to finish fourth and go through as a fastest loser, but Serena Bundy-Davies finished last in her heat.