Ding Junhui's bid for a historic fourth straight ranking title was ended and Judd Trump also crashed out in the last 16 of the UK Championship on Wednesday.
Ding had won the Shanghai Masters, the Indian Open and the International Championship, and victory in York would have brought him the longest run of ranking triumphs since Stephen Hendry's five in 1990.
But Ricky Walden pulled out a hard-fought 6-4 win after a tense finish to the 10th frame.
And Mark Allen came from 3-1 and 4-2 down to beat world number four Trump 6-4 at the Barbican Centre.
Reigning champion Mark Selby had a low-key 6-2 win over Graeme Dott while Stuart Bingham beat Irish surprise package David Morris 6-1.
Dott's defeat ended his hopes of qualifying for next month's Masters, meaning Joe Perry's place is assured ahead of his last-16 clash with close friend Neil Robertson.
Trump led 3-1 despite a 98 from Allen in frame three and remained clear at 4-2 before Allen pulled one back.
Both players had chances in a scrappy eighth frame, Allen responding to one of Trump's misses by hugging his opponent as he returned to his chair.
It came down to the black and after Trump missed a tough pot with the rest and then pushed the ball over the middle pocket, Allen potted it to level at 4-4.
He took the next with a break of 65 and made 54 off a fluke in the 10th, before another piece of luck left Trump hampered by the blue and he handed Allen a frame-winning chance.
Trump was frustrated to lose after a performance from Allen which he described as "awful".
The Bristolian added: "It just turned into a bit of a club game, to be honest.
"It's frustrating because I felt like so far, I've played the best snooker in the whole tournament."
Allen agreed with Trump's assessment and said: "I don't know how I've won that game, to be honest.
"I was really poor from start to finish, but one of my qualities is that I don't give up. I'm pretty proud of myself for coming back from 4-2, even though Judd let me off the hook."
Earlier, Ding trailed 3-1 at the interval but made 76 in the first frame back and levelled at 3-3, only for Walden to win the seventh on the black with a superb pot.
He moved 5-3 clear before Ding pulled one back with a 135 and the next lasted more than 50 minutes, coming down to a battle on the pink.
Ding missed a simple chance and left an equally straightforward one which Walden took.
The Chinese player said of the fateful pink: "My cue action didn't work, the cue turned in my hand.
"It's difficult to play Ricky, he gave very few chances. Every frame he scored heavily and he didn't leave any long ones, it was good safety."
Walden added: "It was pretty tense towards the end, we both had a couple of chances to win that frame.
"I was sat in my chair ready for a decider. I got a bit of luck there but thankfully today was my day.
"I'm just happy that I'm still batting."
Selby had four half-centuries in his win, including an opening 73.
But a 34 clearance in frame six was the key to seeing off Dott, who described losing the frame as "a big blow".
"I knew it was going to be tough, and it turned out to be tough," said Selby.
"I've ended up winning 6-2 but it could have easily been 3-3 - I took a good finish out to go 4-2 which might have ended up being the turning point."
World number 93 Morris looked assured early in his game, with breaks of 41 and 64 to win frame two, but Bingham responded and led 3-1 at the interval.
Breaks of 60 and 54 saw him towards victory but he said: "It was a bit of a flattering scoreline.
"David made it tough for me early on and I was lucky to be 3-1 up - he had chances to be 3-1 up himself.
"I came out after the break and put a couple of good breaks together, to go 5-1, and then got over the line."
World champion Ronnie O'Sullivan faces Robert Milkins in the evening's other game.