The Crusaders have extended their unbeaten record in this year's Super 12 with a remarkable comeback to beat the Cats 37-30.

Trailing in the first half 27-3 after tries from Andre Pretorious (2) and John Daniels the Crusaders responed with tries of their own from Ben Hurst, Corey Flynn, Leon MacDonald and Marika Vunibaka to seal the win and clinch the bonus point.

A brilliant performance by Crusaders flyhalf Andrew Mehrtens earned his team their ninth consecutive Super 12 win when they edged the Cats 37-30 in a thrilling match played at Ellis Park on Friday.

Ironically, the result marked the first time Mehrtens has won a match against South African opposition at the Johannesburg ground.

Mehrtens converted seven out of seven kicks - three penalties and four conversions - as the Crusaders booked a home semifinal with their five points earned in the match.

Opposite number Andre Pretorius almost stole Mehrtens' thunder with a breathtaking display, scoring two brilliant tries and kicking three penalties and three conversions for a personal tally of 25 points.

Pretorius is surely destined to face Mehrtens again in this season's Tri-Nations, putting in a masterful display.

The Crusaders, after trailing 24-0 at the quarter mark and 27-17 at the break came back brilliantly and tied the scores at 27-27 in the 47th minute.

The visitors, after finishing the first half on top, continued where they left off and a Mehrtens penalty was followed by a converted try through outside centre Leon MacDonald.

Pretorius then slotted an easy penalty in front of the poles in the 56th minute to give the Cats a slender 30-27 lead, but Mehrtens answered with a difficult attempt to once again level matters at 30-30.

After the high-scoring heroics of the first half, the second half stagnated into a period of concerted pressure, marked by a series of unforced errors by both sides.

Pretorius nearly picked up a hat-trick in the 68th minute after charging down a Mehrtens kick and racing to the line, but the video referee ruled that he had knocked on with three Crusaders defenders on top of him.

With four minutes remaining Pretorius again almost sent the Cats into the lead, but his long distance drop-goal sailed inches wide.

The Crusaders stole the show when substitute winger Marika Vunibaka scored their fourth and bonus point-earning try out wide. Mehrtens added the conversion and the visitors led, for the first time in the match, 37-30.

Scorers:

Cats - Tries: Andre Pretorius (2), John Daniels; Conversions: Pretorius (3); Penalties: Pretorius (3).

Crusaders - Tries: Ben Hurst, Corrie Flynn, Leon MacDonald, Marika Vunibaka; Conversions: Andrew Mehrtens (4); Penalties: Mehrtens (3).