Regent left it late to seal their place in the third round as a try seven minutes from time gave them a 14-13 victory over Portora.
It was a tight game throughout, with Portora going ahead through a Reece Smyton penalty. Regent had their share of possession but could only break out a few times in the first-half.
The second period was equally competitive with the Enniskillen team increasing their lead through a Dylan Crawford try.
Seven minutes later, home captain Tom Arthur Donnan won line-out ball and the forwards rumbled ahead and he scored for Adam Currie to goal.
Portora retorted with an excellent try when a superb break on the 10-metre line by Robert Baloucoune led to Josh Kennedy diving over.
After some excellent scrummaging with seven minutes remaining, Regent's Kyle van Giesan won the ball against the head and No.8 Ryan McCarroll crossed for Currie to add the points.
Portora then won a couple of penalties and kicked to the corner but Regent held out to progress.
Regent coach Mervyn Tweed was thrilled. He said: "It was a tremendous effort. Lewis English is a quality player. We had 90 per cent of line-out possession and Tom Arthur Donnan was everywhere.
"He kept his cool as captain and we needed a last-ditch effort to keep them out. Kyle van Giesan was once again superb and is improving with every game."