Britain's Jason Kenny moved closer to an individual sprint medal to go with his team gold after beating Malaysia's Azizulhasni Awang in the last eight.
Kenny won 2-0 and will take on Trinidad's Njisane Nicholas Phillip on Monday, with the winner going into the gold medal final.
Four-time world champion Gregory Bauge of France meets Australia's Shane Perkins in the other semi-final.
In the women's sprint, Victoria Pendleton eased into the last eight.
Kenny, the top seed after qualifying fastest in an Olympic record for a flying lap, remains on course for a much-anticipated showdown with Bauge, who narrowly beat him in the World Championships in Melbourne in April.
Bauge has won the last five world titles, but lost his 2011 crown to Kenny after being given a backdated suspension for doping offences.
Phillip is not expected to trouble Kenny, who brushed aside the erratic Awang, but the Briton will be aware the charismatic 21-year-old shocked Germany's Robert Forstemann in the second round.
Bolton-born Kenny, who took individual silver behind Sir Chris Hoy at the Beijing Games, was chosen ahead of Hoy for London 2012 after rules restricting each nation to one rider per event were introduced.
The 24-year-old teamed up with Hoy and Phillip Hindes to kickstart Team GB's gold-rush in the velodrome on Thursday night, beating a French trio including Bauge in the final.
Meanwhile, Pendleton continues to look in supreme form following her gold medal in the keirin.
The defending sprint champion, who also broke the Olympic record in qualifying earlier on Sunday, surged past teenage Russian Ekaterina Gnidenko with half a lap to go in her first-round match before making short work of Willy Kanis of the Netherlands with another comfortable win.
Pendleton, 31, who retires after these Olympics, is hoping to sign off with her second success in London.
Her great Australian rival Anna Meares also made perfect progress to the last eight, with the competition continuing on Monday.