SHEFFIELD — Five-time winner Ronnie O'Sullivan was on the verge of a quarterfinal place in this year's snooker World Championship after going 12-4 up against Matthew Stevens Sunday. Meanwhile Australia's Neil Robertson, world champion in 2010, continued to dominate his match against two-time runner-up Ali Carter. Robertson, 6-2 up overnight, lost the first frame of Sunday's play but then won the next five to go 11-3 ahead before his English opponent avoided the embarrassment of losing with a session to spare by taking the next two frames to leave the ‘Thunder from Down Under' well-placed at 11-5 in front. — Agencies