After a slow start to the game, last year's UK Championship runner-up cut loose after the interval to earn a last-32 meeting with Grand Prix champion Stephen Lee.
His 138-break in frame five is the highest of the tournament so far and he finished with a 79.
Stevens said: "I didn't get much practice for this event while we were in Newcastle, but winning the event has given me confidence. And that is more important than the practise. Both John and I were a bit edgy at the start and, even though I finished strongly, I'll need to do better against Stephen. He is one of the best players. But I beat him 9-6 at the UK Championship so I won't be worried."
Stevens, the provisional world No 9, certainly has a chance of becoming only the second Welshman to win the title after Nations Cup hero Mark Williams in 1996. Last night Lee defeated Matthew Couch 5-3 including three century breaks and a 90.
The Dubliner Fergal O'Brien gave himself a tonic after the Republic of Ireland finished up with the wooden spoon on Tyneside last week. The world No 20 defeated qualifier Allister Carter 5-2 and provides the next opposition for the defending champion, Paul Hunter, while Patrick Wallace yesterday notched a 5-3 victory over the 1997 world champion, Ken Doherty. He was always in command against the Republic of Ireland's Nations Cup skipper. Ulsterman Wallace's best moment was a break of 121 in the sixth frame and he also added runs of 57 and 43.
Doherty, the world No 4, becomes the third and highest top 16 seed first- round faller. He said: "I'm blowing hot and cold this season and today I was freezing."Reuse content