Neil Robertson was stunned in Riga as World number 96 Lukas Kleckers dumped him out of the traditional season curtain-raiser in the German's first professional contest.
Bingham also departs after lacklustre opening display
Despite leading 2-1 and 3-2, Robertson could not hold off the 21-year old who held his nerve with an excellent final frame decider break of 83 after only turning professional several weeks ago.
2015 World Champion Stuart Bingham was another big name to end up on the receiving end of a surprise result as Mark Davis knocked him out of the competition with a 4-0 victory. Both former Crucible heroes will now have to head back to the practice tables after weeks of preparation slipped away.
Yet the number three and five seeds were not the only top twenty players to show a level of shady form. Michael White was also on the receiving end of a 4-0 defeat to Sam Baird, whilst number two seed Barry Hawkins lost the tie of the round against Ryan Day in a final frame decider.
Veterans White, Doherty and Williams progress
Tom Ford did not register a frame as he was defeated by the ever-improving Hammad Miah, whilst Alan McManus was also stunned by Kurt Maflin, 23 places his inferior. Jamie Jones had 39 places on Sam Craigie but also fell at the first hurdle.
Jimmy White and Ken Doherty made the most of their invitational tour cards with opening victories, whilst top ten players Anthony McGill, Kyren Wilson and Mark Williams all progressed.
Slessor loses to Ursenbacher without potting a ball
Yet one of the performances of the first round undoubtedly belonged to Swiss youngster Alexander Ursenbacher. After a couple of seasons showing his potential, winning the European Youth Championship last year, Ursenbacher set the highest break of the tournament thus far with a 139 in the opening frame.
However, that moment only portrayed half of the tale. Ursenbacher went on to score 381 points to Elliot Slessor's four. Yet Slessor's four were also scored by Ursenbacher after a foul, leaving Slessor exiting the tournament after failing to pot a single ball.