The Melbourne Rebels have become the latest Super Rugby roadkill for the ladder-leading Crusaders, falling to a 41-19 defeat at AAMI Park.

Heaping more misery on the hapless Rebels, their Wallaby backrower Sean McMahon appeared to have broken his arm to end his hopes of playing in Australia's Test series next month.

McMahon was playing only his third game of the season after returning from injury but went down after making a tackle in the 73rd minute and was immediately taken to hospital for further treatment.

With the last-placed Rebels playing the unbeaten frontrunners, it was always going to be a matter of how big the margin.

To the Rebels credit, it wasn't as big as expected.

The loss meant it's now 20 matches - including this entire Super Rugby campaign - since an Australian team has beaten a team from New Zealand.

The Crusaders, who rested many of their All Blacks, ran in six tries to three in an entertaining game, despite the dominance of the visitors.

The home side actually won the second half on the scoreboard.

"We were pleased with the second half but the game goes for 80 minutes," Melbourne coach Tony McGahan said.

"We let ourselves down in the first half with a few things - inaccurate kicking, turnovers in the green zone, and we were unable to connect on defence."

The 25th minute yellow card to centre Reece Hodge for a deliberate knockdown as the Crusaders edged toward the tryline proved costly with their opponents adding 21 points to their tally.

Melbourne's Japanese international No.8 Amanaki Mafi was a stand-out performer, unfortunately they needed another 14 to follow his lead to match the might of their opponents.

The Crusaders led 31-7 at halftime, with Jed Brown scoring a double and the Rebels' league recruit Marika Koroibete crossing for the first of his two tries from a clever move off the line-out with Colby Fainga'a throwing a sweet backhand pass.

The hosts started the second half on a positive note with prop Toby Smith burrowing across for a try but as was the case with each Melbourne try, the Crusaders replied within minutes.

Koroibete's second try came in the 58th minute after a burst downfield by Mafi, who finished with 149 run metres, almost double the next best of the Rebels.

The Rebels continued to toil hard but mistakes and missed tackles proved costly against the competition benchmark.

All Blacks veteran winger Israel Dagg made a positive return in his first game since round three for the Crusaders with coach Scott Robertson saying they got what they wanted out of the match.

"We wanted to come away with a performance we were proud of and we wanted to play quick and fast rugby, and we did that," he said.

"We probably did always execute when we could have and left a lot tries out there but that was pleasing all the same."