The Kiwi ambush of Australian rugby is complete with a breathtaking 33-32 win for the Crusaders over the Brumbies in Christchurch.

An Aaron Mauger field goal with one minute remaining proved the difference after the Brumbies snatched a 32-30 lead in the 76th minute after earlier trailing 30-18 with 20 minutes left on the clock.

The Brumbies scored four tries to two, but the class of Crusaders five-eighth Andrew Mehrtens guided the Crusaders to victory with five penalties, a field goal and a conversion for a personal tally of 20 points.

The Crusaders remain the only undefeated side after six rounds, but sit in fourth spot with a game in hand and only one bonus point. The Brumbies retain the competition lead after collecting two bonus points for finishing within seven points and scoring four tries.

All three Australian sides return across the Tasman with their tails between their legs after the Blues edged out the previously undefeated Waratahs 22-20 on Friday night and the Hurricanes beat the Reds 22-20 on Saturday.

It was a spectacular weekend of rugby with just five points the biggest winning margin from four games. The Chiefs had earlier scored an upset 29-24 win against the Highlanders.

But there is no doubt after this high quality showing with the lead changing five times that the Crusaders and Brumbies remain the front-runners to contest the final.

While Mehrtens continues to enjoy a brilliant season, his combination with inside-centre Aaron Mauger was decisive. But their performance was slightly shaded by that of Brumbies flanker George Smith, whose work rate around the field was unmatched.

The Brumbies led 15-14 at half-time, but a 16-point burst, with 11 to Mehrtens, in 20 minutes after the break gave the Crusaders a 30-18 match-winning advantage.

The Brumbies have made an art form of soaking up opposition pressure and then coming home strongly this season. But the Crusaders outplayed them after half-time and it wasn't until there were 10 minutes left on the clock that the Brumbies sparked a revival.

Replacement centre Tim Atkinson reduced the lead to 30-25 in the 70th minute and six minutes later the Brumbies snatched a 32-30 lead through a Stephen Larkham try that was superbly converted by Andrew Walker from just inside the sideline.

Scoreboard

CRUSADERS 33
Tries: Caleb Ralph, Joe Maddock.
Goals: Andrew Mehrtens 5 pen goals, goal, drop goal; Aaron Mauger drop goal.

ACT BRUMBIES 32
Tries: Stirling Mortlock, Jeremy Paul, Tim Atkinson, Stephen Larkham.
Goals: Andrew Walker pen goal, 2 goals; Stirling Mortlock pen goal, goal.