Ronnie O'Sullivan qualified for the second round at the Crucible for the fourteenth consecutive year but he found life difficult against qualifier Gary Wilson as he began his quest for a sixth World Championship crown.
It was to be a similar story for Kyren Wilson who was pushed to the limit in a testing match against another player ranked outside the top 50, David Grace.
Qualifiers show their spirit
After being pegged back from 5-1 to 5-4 in the first session, O'Sullivan had it all to do against Gary Wilson. The World number 59 began the second session with a break of 50 but it was not enough to win the frame as the Rocket powered through. However, Wilson ensured he did not make the same mistake minutes later as he produced a maiden Crucible century to keep in the contest.
That moment seemed to spark O'Sullivan into life as he made contributions of 124, 74 and 83, with the first being the highest break of the tournament thus far. Three consecutive frames put O'Sullivan within one of victory but Wilson was not done as he fought back with two more frames, underpinned by a 103 in the sixteenth. Yet the multi-World Champion put the game to bed with a break of 90 to edge through 10-7.
On the opposite end of the spectrum to O'Sullivan in terms of his career, Kyren Wilson had similar problems on the other side of the divider. David Grace had proved in the opening session that he was made of a tough skin and the pair exchanged two tight opening frames on day two as Wilson remained just ahead at 6-5.
Wilson eased through the twelfth, only for Grace to secure his first Crucible century with a 104. Yet it was at that point that the World number 51 ran out of steam and Wilson showed his ability to win three consecutive frames. A break of 93 set the youngster on his way as he mustered a 10-6 victory.
Murphy hits top gear whilst Ebdon digs in
O'Sullivan will face either Shaun Murphy or 17-year old superstar Yan Bingtao in the second round. After the first session it looks as though it will be the 2005 World Champion despite a spirited display from the Chinese youngster. Unfortunately for Bingtao he met Murphy in great form as he racked up breaks of 52, 54, 112 and 118 on his way to four of the opening five frames. Bingtao did secure his first ever century break at the Crucible in his maiden frame win but a 4-1 down the task to qualify was already looking tough.
The World number 63 fought back with a tactical victory in the sixth and a break of 67 in the following frame but Murphy soon stepped on the accelerator again as he won the final two frames of the session, culminating with a break of 81, as he took a 6-3 lead overnight.
Two former World Champions also met in the afternoon session with Stuart Bingham failing to shake off the attentions of Peter Ebdon. The 2015 World Champion looked to be cruising the contest as he took the first three frames with breaks of 91 and 80.
Ebdon is a grafter and struck back with two of his own, only for Bingham to take his game up a gear with compilations of 74 and 122. Ebdon hit back again to leave the score 5-3 before a quite remarkable final frame unfolded. A break of 66 from Bingham left Ebdon needing four snookers to force a re-spotted black and Ebdon did just that before winning the frame on the final ball.
Marco Fu has it all to do
Sunday's play culminated with a potential shock on the cards. Marco Fu has been in great form this season but he found himself 7-2 down to World number 30 Luca Brecel. The Belgian showed his class as breaks of 55, 109 and 94 helped him to five consecutive successes as Fu failed to score.
The Hong Kong player registered in the sixth, only for Brecel to take another frame with 72. Fu did show his class with a break of 105 to end the session but has it all to do as he looks to formulate a remarkable comeback.
Northern Ireland's Mark Allen had to dig deep to gain an overnight advantage against World number 39 Jimmy Robertson. The qualifier made breaks of 55 and 86 as he won three of the opening four frames, with Allen scoring 63 in the third.
Allen responded after the interval with a compilation of 105 before Robertson hit back again with a 78. Yet three frames in a row for the World number eight, including a century break in the final frame, gave Allen a 5-4 overnight lead.