Super Rugby Aotearoa champions the Crusaders survived a second-half fightback from the Brumbies to start their Trans-Tasman campaign with a dramatic 31-29 win.

The Crusaders appeared to be on course for a comfortable victory when they led 19-7 at the interval thanks to tries from Ethan Blackadder, Richie Mo'unga and David Havili.

Irae Simone's try and five points from the boot of Noah Lolesio trimmed the gap to two points after the break, only for Brendon O'Connor and Cullen Grace to cross to restore the Crusaders' measure of command.

But Tom Banks' try and Lolesio's conversion restored hope for Super Rugby AU runners-up the Brumbies, who then moved within two points of sending the game to extra time when Tom Wright's inside pass sent Rob Valetini over in the last minute.

However, this time Lolesio could not find the desired accuracy from the tee, his kick from the sideline sailing just wide of the left-hand post as the Crusaders clung on.

There was a markedly similar end to the Chiefs' 20-19 victory over the Western Force.

The Chiefs led 10-7 at half-time and tries from Nathan Harris and Jonah Lowe appeared to put them in control.

But Luke Jacobson's 66th red card, which came after he received a second yellow for slowing the ball down at the ruck, gave the Force new life.

They made their one-man advantage count three minutes later as Richard Kahui went over and had a chance to snatch victory at the last after Domingo Miotti crossed.

Miotti, though, could not convert his own try, sending the attempt agonisingly wide of the uprights.

That kick ensured it was a clean sweep for New Zealand sides over their Australian opponents, the Blues having run in eight tries in trouncing the Rebels 50-3 earlier in the day.