Crusaders maintained their perfect Super Rugby record this season by winning a fiercely contested battle with Hurricanes 20-12 at AMI Stadium, while Highlanders continued their winning run at Bulls on Sunday (AEST).

A game billed as arguably the biggest round-robin Super Rugby encounter of all time proved to be an almighty tussle and it was Crusaders who came out on top against the defending champions in Christchurch.

The free-scoring Hurricanes were unable to come up with a solitary try for the first time in the competition since February 2014, but Matt Todd bulldozed his way over for the only four-pointer of the game as Scott Robertson's side made it 11 wins out of 11.

Three penalties apiece from Richie Mo'unga and Jordie Barrett ensured the two heavyweights were level at 9-9 at the end of a first half in which a slippery ball made life difficult.

An elusive first try came 11 minutes after the break, though, when Todd got the ball down following a lineout catch and drive, rewarding Crusaders for piling on the pressure.

Crusaders prevented Jordie Barrett and his brother Beauden from pulling the strings, although the former was able to add another penalty to cut the gap to 17-12 following another from Mo'unga.

Fly-half Mo'unga restored Crusaders' eight-point advantage from the tee five minutes from time and there was no way back for Hurricanes as the hosts continued their march towards securing top spot in the New Zealand Conference.

Highlanders have now won seven in a row, but needed a late Malakai Fekitoa try to defeat Bulls 17-10 in a scrappy encounter at Loftus Versfeld Stadium that saw both sides have a man sent off.

Matt Faddes scored the only try of a first half which ended with the 2015 champions leading 10-3, but Bulls were level early in the second half courtesy of a converted Warrick Gelant score.

Waisake Naholo was dismissed for a shoulder charge at the ruck with 16 minutes remaining in testing conditions on a heavy pitch, but Bulls were also down to 14 when RG Snyman saw red before Fekitoa charged through the middle to settle it with a decisive try.

Rebels are now four without a win after Samu Kerevi's second try of the game with time running out gave Reds a 29-24 win at AAMI Park.