Chinese wild card Tian goes through to the quarter-finals to face Joe Perry, while Pokerstars.com Masters champion Selby faces a return flight to the UK.
The Jester made a strong start with breaks of 72, 61 and 129 helping him to a 3-1 lead, but that form deserted him after the interval as Tian took charge. The home favourite won four consecutive frames with top runs of 69, 61 and 67 to reach the last eight.
Ryan Day was also given a tough examination, but he came through 5-4 against Yu Delu to earn a meeting with local hero Ding Junhui.
Welshman Day came from 2-0 down to lead 3-2 with breaks of 52, 62 and 65. Yu levelled with a 67, then Day regained the lead with a 98 before his opponent forced a decider. It was a scrappy conclusion but Day won it 54-26.
* Tiberiu Iacomi recently interviewed Selby and has sent in this Q&A:
You have appeared in the final of the Betfred.com World Championship, and you reached the semis this year. Is there pressure on you to win it?
Obviously winning the World title is my ultimate ambition, but there is no pressure. I will continue to work and prepare hard to give myself the best chance.
What new elements did your manager, Mr. Mukesh Parmar, bring to your game and your attitude toward the game?
Management, coaching, organisation and his positive attitude. He gives me belief. Also he is a friend and companion. Travelling can become quite lonely!
You have proved yourself a master of exceptional comebacks and cool nerves. Is this a gift or is it psychologically trained?
Itís a question of inner belief and never giving up, the match is never over until the last ball is potted!
How do you envisage yourself in snooker when you finish playing? Opening a snooker academy, investing in snooker promotion or being a coach and a mentor for young players?
Yes, having my own club and academy is definitely a goal of mine, but coaching and mentoring Ė Iíll leave that to Mukesh!
Are you excited about snookerís future?
Well, with the appointment of our new chairman Barry Hearn, hopefully he will generate more tournaments and bring more sponsors into the game.
What impact did snooker have on your childhood and personality?
I started playing pool at 7 and snooker at 9 years old. It instantly gave me an interest and a hobby, but it kept me off the streets and any chance of getting into trouble! Also it surrounded me with adults so I grew up quicker.
Even though your are only 26, you have been playing professional snooker for 10 years now. Has that experience, combined with your talent, made you a better player?
You cannot take away the experiences that I have learned. You grow stronger and wiser through the years, though that doesnít mean that the game gets easier! But I am managed well now and more focussed on achieving my goals.
How much do you think that confidence increases your tactical and technical capabilities?
Confidence is everything! When your levels of confidence are high then you feel that you can achieve anything, when itís low everything seems a struggle!
What influence do the fans have during a big final?
Fans are vitally important. Itís harder for me to play in front of a small audience then it is in front of a full arena.
If you were to be chosen a snooker ambassador, in which country would you first promote snooker?
Apart from the UK, possibly China because of the interest and the commitment they have shown for snooker.
How much of your practice time do you allocate to playing pool?
I donít play pool any more.
Which is the best present you have ever received?
The gift to play snooker!!
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