It was a day of high-profile casualties at the Welsh Open.
Three of the world's top 10 fell in the last-32, including Judd Trump - who saw his best-of-seven winning streak come to an end after 28 matches.
The World No.1 arrived in Newport looking for his fifth ranking title of the season but was stunned by Hossan Vafaei, and slammed the conditions.
"It's just so heavy here," he said. "It's difficult to play in. It's like playing in China and that's why the standard has been poor.
"A lot of my games have been bad. Balls are going safe a lot more often, which doesn't make for good viewing.
"It's difficult to play in. People on the outside who stick the tables in there don't play snooker in there, so they just set it up and think it all looks good. When you're out there playing, it's a different story. In those conditions, anyone's going to be able to win."
World No.5 Kyren Wilson also took aim at the conditions after his 4-3 defeat to Tom Ford, while John Higgins was beaten by the same scoreline by Ali Carter.
Mark Williams was the first player through to the last-eight after beating Trump's conqueror Vafaei while reigning champion Shaun Murphy will play Stephen Maguire in the quarter-finals.
Northern Ireland pair Mark Allen and Jordan Brown were battling to keep their Welsh Open campaign going last night after scares in the third round.
Allen's clash with Carter was set for a late finish after only starting at 9.30pm while Brown was hoping to complete a second fightback of the day after falling 3-2 down against Mark King.
The World No.81 had trailed 3-1 against Alexander Ursenbacher in his third-round clash but regained his composure to reel off a 64 break and halve the deficit.
Brown limited his Swiss opponent to just six more points.
Allen also had to come from behind in the last-32 after Scott Donaldson took the first two frames. The World No.10 responded with consecutive half-centuries only for the Scot to make it 3-2. But back-to-back visits of 94 and 72 sealed Allen's progress into the last-16.
Watch the Welsh Open live on Eurosport, Eurosport app and stream on discovery+