Former runner-up Judd Trump took a convincing 6-3 lead over Dominic Dale in the first round of the World Championship at the Crucible.
The world number three knocked in breaks of 88, 82 and 50 as he took control of the encounter.
He stroked in a further 142 - the highest break of the tournament - but Dale hit back with a 50 in the last.
Ding Junhui showed why many pundits make him a contender by taking a 7-2 lead over Alan McManus in their match.
The Chinese star trailed the veteran Scot 1-0 and 2-1 in the first round clash but a flawless break of 131 and a 67 levelled it at 2-2.
A magnificent 129 and further breaks of 61, 51 and 81 helped the world number nine make it six frames in a row ahead.
Both matches play their final session at 10:00 BST on Wednesday.
Marco Fu punished some careless play from Matthew Stevens to move 6-3 clear.
The Hong Kong cueman surged into a 3-0 lead, aided by a break of 70 in the third frame, before an 83 got the Welshman - twice a Crucible runner-up and six times a semi-finalist - on the board.
But Stevens missed chances in the fifth and sixth frames as Fu extended his advantage to 5-1, including a superb 71 break.
Stevens won a much-needed frame after a re-spotted black and a 74 in the next cut the gap to two, but Fu took the final frame of the session.
They will resume at 14:30 BST on Wednesday.
World number one Mark Selby leads Matthew Selt 6-3 after the first session, with the Romford man launching a comeback having gone 4-0 behind.
The two resume at 19:00 BST on Wednesday.