Ding Junhui reacts after losing 17-15 to defending champion Mark Selby at the World Snooker Championship semifinal in Sheffield, England, April 30, 2017. [Photo/Xinhua]

SHEFFIELD, England - China's Ding Junhui was stopped by defending champion Mark Selby 17-15 in a thrilling semifinal at the World Snooker Championship on Saturday.

World number four Ding, who upset five-time champion Ronnie O'Sullivan in the quarterfinals, lost to Selby again following last year's defeat in the final, which finished 18-14.

The two players were deadlocked at 12-12 going into the fourth session and it was Selby who made the first move with breaks of 74 and 96 to go 14-12 ahead.

Ding made a 52 in winning the next and had a clear chance in frame 28 but missed a red to a top corner when trailing 34-41. Selby eventually took the frame on the colours to lead 15-13 at the interval.

In frame 29, Ding led 42-11 when he was unlucky not to split a cluster of reds in potting the pink. Selby made 42 then trapped his opponent in a snooker on the yellow which yielded the chance to go 16-13 ahead.

Ding hit back to take the next two frames with a top run of 73 to close to 16-15. And he had two scoring chances early in frame 32 but scored just nine points, missing a red and then a blue to a center pocket. His second error proved his last shot as Selby made a flawless 72.

Selby, who won the champion in 2014 and 2016, will now face John Higgins over 35 frames on Sunday and Monday for the famous trophy and 375,000-pound top prize. It's a repeat of the 2007 final which Higgins won 18-13.

Ding said after the match: "If I hadn't missed that blue it would definitely have gone to a final frame. Mark played well in the end. I should have won more frames and taken my chances earlier in the session. I had too many mistakes but that is what happens.

"I can see myself improving a lot, I played with more confidence and more aggression. The fans need to see more snooker like that. They want to see fast snooker and centuries. I'm happy with how I did this time.

"I'm disappointed to lose when I played well, but sometimes you have to take it, because it is sport. I've got more experience here, I'm just over 30 and there is still a long way to go and many years left here. I believe next year will be good."

Selby spoke highly of the Chinese star, "I was over the moon to come out 12-12 last night because I thought Ding probably deserved the lead. He scored better than me, he played great, his safety was good, he had three centuries last night. All that you're asking for is to be going into that final session with a chance.

"This year he knew what to expect on the one table set up and I thought he played fantastic. It was only one or two balls here and there that was the difference between me winning or him winning. As a player he's matured, as a person he's matured, his temperament around the table is fantastic. It's only a matter of time before he comes here and wins it."

"It was a great game to be involved in. Ding missed that blue in the last frame, I had resigned myself to going 16-16.