Sydney University's eight-game winning streak was put under immense pressure at Rat Park on Saturday, but the competition heavyweights produced the resolve to capture a win in the second part of the Shute Shield split round 13.
Warringah beat the Students 23-18 in round four and seemed on course for an upset when they held a 12-7 lead at half-time.
The Rats continued to go blow for blow with the favourites in the second half, before Melbourne Rebels forward Tim Davidson came on and scored a try to put the visitors in front, a position they would not relinquish, despite the Rats' valiant efforts and finishing a man down. It ended two tries apiece, with the accurate boot of University's Byron Hodge proving the difference.
Each side crossed over early in the match. Jock Merriman grabbed University's opener after some neat stepping by five-eighth Stephano Hunt and Warringah replied quickly when fullback David Feltscheer found a gap and offloaded to halfback Josh Holmes to make it 7-7.
The half settled into an expansive and entertaining contest. Warringah pressed hard and after a multi-phase attack midway through the half, Feltscheer scooted along the touch line for his sixth try of the season.
The Rats grew in confidence. By half-time they had held 57 per cent of possession and the Students had turned over the ball 14 times.
Sydney Uni lifted after the break. But again the Rats forced errors in the Students' set pieces, including their strong scrum, forcing a change of personnel, including the decisive introduction of Davidson.
There were moments of individual Students brilliance but raids were thwarted by desperate defence and counter-attack.
A penalty goal 55 minutes in brought University within two points. But the Rats dug in and continued to repel in the face of adversity.
A crucial moment came when, after a near length-of-the-field attack - and a video referee's investigation - Warringah five-eighth David Harvey was denied a try, judged to have been held up over the line.
The sides swapped penalty goals soon afterwards, leaving the gap at 15-13 entering the last quarter. A break by James Dargaville got Uni on the attack yet again but they, too, were held up over the line.
Fatigue was taking its toll on the Rats and Davidson grabbed the ball from the back of the scrum with 10 minutes remaining and burst over for a try, converted by Hodge.
With seven minutes left, at 20-15, referee William Houston yellow carded Hunt. But the Students would not allow themselves to be beaten again by Warringah.