Pics: Tai Chengzhe
Selby, who could regain the world number one spot from Judd Trump this week, was set for a perfect score in the third frame after taking 15 reds with blacks. But in potting the pink he left the cue ball just a couple of inches away from the left-hand side cushion, and rattled the last black in the jaws of a top corner.
He unwillingly became a member of the small group of players to have missed the black on 140 in professional competition, the only others being Ken Doherty, Barry Pinches and Robin Hull. The maximum would have been the second of Selby's career and would have earned him £20,000 from the 147 rolling prize pot plus £3,500 for the tournament high break.
On the plus side for the UK and Masters champion, he produced one of his best performances of the season as further runs of 111, 82, 91 and 104 helped him set up a last 16 match with Ricky Walden.
"I'm really happy to win and to play that well is very satisfying," said Selby. "It's been a while since I played that well. I have come here to find a bit of form ahead of the World Championship so it's a good start."
As for the missed 147 he added: "I left myself a really tough black, it wasn't nerves it was just a tough shot and I missed."
Neil Robertson also looked sharp in a 5-0 whitewash of Jimmy Robertson, highlighted by runs of 72, 58, 70 and 70.
"Jimmy had his chances early on but missed a few balls and never recovered mentally from that," said world number three Robertson. "I played some good frames and I'm pretty happy with my performance. I know how well Jimmy can play because he beat me in a PTC event in Prague a couple of years ago and he had three centuries in his first round here.
"John Higgins, Ding Junhui and Judd Trump are out but there's still a lot of great players left. My season has been very consistent, the only thing missing is a major win. I'm just hoping to maintain my form and to get a bit of luck.
"In the past I wasn't getting to many semis or finals, but when I got there I was winning them. This season I've got to the latter stages a lot but lost three close finals. It's not that I'm failing to finish matches off, I just haven't had the luck that I've had in finals in the past."
In-form Mark Allen, aiming for a Chinese double having won the Haikou World Open last month, stormed to a 5-1 win over Anthony McGill with top breaks of 92, 129 and 56.
"I started off strongly and put him under pressure early on," said Allen, who meets Robertson next. "Maybe Anthony was a bit nervous because he hasn't played at many venues before, and I was able to capitalise on that. My form has been good in 2013 and I've kept that going."
Stuart Bingham top scored with 81, 90, 79 and 91 in a 5-3 defeat of Liang Wenbo, which means there are no Chinese players in the last 16. "It was a good battle," said Bingham. "Liang's a very good player. I felt I was on top for most of the game but he kept clawing his way back. Thankfully I got the job done in the end."
Ball by ball scoring and results from tournaments