Mark Selby lost just one frame as he got his China Open bid under way in Beijing.

The world No.4 was a 5-1 winner over Stephen Lee in yesterday's first-round clash at the Beijing University Students Gymnasium.

Selby was on form after losing the opening frame, firing in a series of breaks – including 105 in the third and 73 in the fifth – as he took the next five on the spin.

He now faces former world champion Graeme Dott for a place in the quarter-finals.

Scot Dott, who triumphed at the Crucible in 2006, was a 5-3 winner against Yu Delu.

In other action in Beijing, Ronnie O'Sullivan fended off a determined challenge from Fergal O'Brien.

The world No.1 trailed 2-1 and, despite winning the next two frames, was then pegged back to 3-3 by Irish cueman O'Brien, who has failed to qualify for this month's World Championships.

But O'Sullivan produced breaks of 55 and 54 to take the next two frames and secure a 5-3 win, setting up a clash with 20-year-old Chinese player Xiao Guodong, who was a surprise winner against Ding Junhui.

Stephen Hendry gained an encouraging victory over Robert Milkins, beating the Englishman 5-3, and Mark King beat Mark Williams 5-2.