Judd Trump and Dominic Dale impressed on Sunday afternoon to get within touching distance of a World Championship quarter-final spot.
After scraping through the first round, Trump had begun this second round tie against Ryan Day in more impressive fashion taking six of the opening eight frames.
But the Bristolian looked a little edgy as he was stuck in his chair for the afternoon's first with the Welshman Day knocking in a 125 and 80 to take two of the opening three frames.
A 61 seemed enough for Day in the 15th, but Trump, world number eight, unleashed his usual brand of fireworks to power in a 64 and steal it.
Day though stayed cool in the final action of the day with a smooth 73 to keep the deficit to four frames at 10-6, but he'll have his work cut out if he is to deny Trump a quarter-final place when they resume Monday evening.
It was another impressive show by surprise package Dale, along with his black and white stripy shoes, and he'll return to the Crucible on Monday afternoon needing just one more frame to reach the final eight.
The world number 24 dominated fellow qualifier Michael Wasley as he continued to revel in the Crucible atmosphere in his first appearance in round two of the World Championship since 2000.
Wasley, conqueror of Ding Junhui in the opening round, struggled again, although he did spark with an early 66 and then a 108 in the penultimate frame of the day.
Overall though, Dale was the star performer and breaks of 78. 89 and 73 were enough to earn a 12-4 lead.
On Sunday evening, world No 1 Neil Robertson edged into a 9-7 advantage over Northern Ireland's Mark Allen in their second-round match.
The opening session had been split 4-4 and there was again not much in it until Robertson won the final two of the day, including a 137 in the penultimate frame to take his tally of centuries for the season to 99, already a tour record by some distance. The match is played to a finish on Monday afternoon from 1pm.
And on the other table, 2005 world champion Shaun Murphy made his move to lead Marco Fu 9-7 going into the final session of their second-round meeting.
Murphy reeled off four in a row to race 8-4 in front before Fu kept in touch by winning three of the last four, finishing off with a 136 break. The match concludes on Monday evening.