Stephen Maguire came from behind to beat Judd Trump 6-4 while Neil Robertson repeated the scoreline against Robert Milkins on the second day of the Masters.
Maguire gained a modicum of revenge over Trump after being defeated by the same margin to the Englishman at the recent UK Championship in York.
But it didn’t always look as though that outcome would materialise.
The Scot went 2-0 down early doors as his long-term battle with his own temperament appeared to be getting the better of him yet again.
However, Maguire came from way back in the third frame to pip it on the black before a 96 in the next somehow ensured they entered the mid-session interval level.
Trump would have been reeling having let what could have been a commanding lead slip from his grasp and by the time he recovered he was already 4-2 down.
The 25 year-old did eventually rediscover his scoring prowess with runs of 109 and 71 setting up a tense finale, but Maguire won the final two frames for a big victory.
Australian Open champion Trump had been one of the pre-tournament favourites having only narrowly been beaten on two occasions by Ronnie O’Sullivan in the finals of both the Champion of Champions and UK Championship.
However, Maguire has returned to form himself over the last few weeks and followed up his unexpected run at The Barbican Centre by claiming the inaugural Lisbon Open trophy in Portugal before Christmas.
The 33 year-old faces Shaun Murphy, conqueror of three-time champion Mark Selby on the opening day, for a place in the semi-finals with the pair having long had a frosty rivalry stretching back many years.
The other tie on Monday saw world no.1 Robertson win three frames on the trot from 4-3 down to Milkins to prevail in another close encounter.
The Australian looked to be in trouble when his challenger won a close seventh frame on the black to take the lead but Robertson moved through the gears and Milkins was left powerless as runs of 95, 117 and 76 from the former champion proved more than enough.
Today, the defending champion begins his quest for a record-equaling sixth Masters crown – a full 20 years after completed his maiden triumph.
Ricky Walden is well-remembered as one of Ronnie O’Sullivan’s opponents in last year’s romp to success, when the Chester cueist sat mostly in his chair and watched as the ‘Rocket’ accumulated a record tally of 556 unanswered points.
Walden will surely do better in this meeting but it is hard to see where a winning challenge comes from, especially as he has openly admitted to struggling with a shoulder injury since his International Championship success in early November.
O’Sullivan must be chomping at the bit having watched two of his biggest rivals exit the competition already and will arguably be looking at Robertson as his primary obstacle in retaining the trophy.
The evening match sees English duo Ali Carter and Barry Hawkins duel for a last eight place.
Carter isn’t technically inside the world’s top 16 at the moment but rightly had his seeding of 13 frozen until the end of the season after his battle with lung cancer in 2014.
That meant that the ‘Captain’ was invited to London this week and, having gained the all-clear from doctors in December, is sure to be given a fabulous reception from the Alexandra Palace crowd.
World number 5 Hawkins must put sentiment to one side, though, and will be desperate to gain his first victory in the tournament on his fifth appearance.
Both matches are on BBC and Eurosport.