Former world champion Shaun Murphy was dumped out of the Gibraltar Open by Chinese outsider Lu Ning.
Murphy, ranked 66 places above his 25-year-old opponent, hit breaks of 83 and 68 to haul a two-frame deficit back to 2-2.
But Lu, who's best ranking finish came with a quarter-final place in India a fortnight ago, rattled in an 85 and a 115 to oust the world number 11.
Amateurs Oliver Brown and David Grace also reached the last 16, the latter beating another former Crucible winner, Peter Ebdon, 4-3 before sinking Chris Wakelin 4-1.