Masters champion Mark Allen suffered an early exit at the German Masters on Wednesday night after a 5-4 defeat to Matthew Selt.
Just over a week ago, the Northern Irishman fought off a spirited performance from Kyren Wilson to lift his first Masters title with a 10-7 victory at Alexandra Palace.
However he came out the wrong side of a ding-dong contest with world number 45 Selt, despite breaks of 97, 72 and 100.
Defending champion Anthony Hamilton crashed out, ensuring the tournament's record of never having a repeat winner will remain in tact.
Hamilton, whose victory 12 months ago was his first ranking title in more than 25 years as a professional, lost 5-1 to Jimmy Robertson in their opening round encounter at the Tempodrom in Berlin.
Robertson moved into a 2-0 lead with the aid of a 73 break in the second frame, before Hamilton hit back with a run of 66 to reduce his deficit.
However, that proved to be the 46-year-old's highest break of the contest and Robertson won the next three frames in succession to advance to the last 16.
Dubliner Fergal O'Brien also fell at the first hurdle, losing 5-3 to Mark Williams.
Fast & furious!
— World Snooker (@WorldSnooker1) January 31, 2018
What a match... #D88GermanMasters pic.twitter.com/nHH0yYwykn
Judd Trump's two century breaks helped him to a 5-3 win over Ben Woollaston. Ricky Walden won the final two frames in a 5-3 victory over Jack Lisowski, and Gary Wilson defeated Martin Gould 5-2.
Ding Junhui showed signs of getting back to his best form with breaks of 55, 131, 56 and 71 helping him to beat Michael Georgiou 5-3, while Joe Perry edged past Yu Delu 5-4 thanks a break of 59 in the deciding frame.