Ricky Walden narrowly avoided becoming another early seeded casualty after coming through a tough battle with debutant Kyren Wilson 10-7.
The Chester cueist, semi-finalist at the Crucible in 2013, appeared to be cruising to a relatively comfortable victory when he led 22 year-old 8-5.
However, Wilson fought back gallantly to trail by only one at 8-7 as his opponent visibly began to look under pressure.
Yet, Walden managed to just about compose himself to book his place in the last 16 following a tense 17th frame that last more than an hour.
In fact, the frame lasted just two minutes shy of the Crucible record for the longest frame at the venue, which was the 75 minute slog between Stephen Maguire and Mark King in 2009.
Wilson, who came through all four rounds in qualifying, will perhaps rue his inability to win any frame after the mid-session interval on the first day’s action, when a 3-1 lead capitulated into a 6-3 overnight reverse.
Still, it was a decent debut for the popular Northamptonshire player, who many predict will be one of the future stars of the baize.
For two-time ranking event champion Walden, it will come as a relief to emerge victorious from a contest that could have potentially been a serious banana skin.
With four seeds already gone by the wayside, the 31 year-old would have been conscious of how the tournament was potentially opening up for those who could mount a challenge early on.
At the end of the day, it doesn’t really matter whether or not he played well as he will now feel a part of the tournament proper having reached the second round.
Elsewhere on Tuesday evening, Mark Allen edged a tight opening bout of play with Michael Holt to lead the ‘Hitman’ 5-4.
The session hinged on a succession of close frames near its conclusion, when Holt won two frames on the black to go 4-3 ahead before Allen stole the next on the pink to level.
The Northern Irishman dominated the last frame to take the slim advantage into tomorrow in a match the 28 year-old will want to avoid becoming his third first round exit on the trot.
Meanwhile, two other contests reached their halfway points.
Judd Trump and Tom Ford played out a dire eight frames that averaged almost half an hour in length, with the 2011 finalist able to establish a 6-2 cushion.
On the other table in the afternoon, Barry Hawkins is 5-4 up on fellow Englishman David Gilbert.