LONDON, April 21 (Xinhua) -- Three-time champion Mark Selby suffered a shock 10-4 defeat to Joe Perry in the first round of the world championship in Sheffield on Saturday.

Selby, who won the title in 2014, 2016 and 2017 at the Crucible Theatre, fell 4-0 and 7-2 behind, and he never recovered.

The world number one took two out of the first three frames in the evening session to make it 8-4. However, from there Perry, the competition's oldest player at 43, sealed the victory with breaks of 76 and 90.

"I'm delighted, chuffed," said Perry. "When the draw came out, I knew I'd have to perform to the best of my ability. Luck was on my side today, I had a few nice little bits of run which I capitalised on. All in all, I'm really pleased with my performance.

Selby said, "The last three or four years I've had some good success here so I can't complain. I'm gutted to lose but if you'd told me in 2014 that in the next three or four years I'd have won it three times I'd definitely have taken that."

In the day's other matches, 2006 champion Graeme Dott took a 6-3 lead over Ali Carter to move within four frames of a last 16 meeting with Ronnie O'Sullivan or Stephen Maguire.

Five-time champion O'Sullivan trailed Maguire 6-3, Marco Fu of Hong Kong, China fell 6-3 behind against debutant Lv Haotian of China after the first session, while Masters finalist Kyren Wilson opened up a 7-2 lead over two-time world runner-up Matthew Stevens.