Prop John Afoa became Super Rugby's oldest-ever player as his Canterbury Crusaders coasted past the New South Wales Waratahs 42-18 on Saturday to remain second in the standings.

Former All Black Afoa played his part after a surprise late call-up as the Crusaders scored six tries to three in Christchurch.

It left their Australian opponents in sixth place, where they are guaranteed to remain ahead of the top-eight finals series regardless of the results in next week's last round of regular season matches.

Fly-half Richie Mo'unga was a try-scorer and did not miss a shot at goal in a 17-point haul as the defending champion Crusaders notched a ninth win from their last 10 games, after making a sluggish start to the season.

A highlight was the starting appearance of Afoa, who from France two days earlier following a plea from coach Scott Robertson, who is without three injured All Blacks -- Joe Moody, George Bower and Fletcher Newell -- for the remainder of the season.

Former Auckland Blues tighthead Afoa had not played a Super Rugby match since 2011 and, at the age of 39 years and 223 days, became the competition's oldest player.

After his 496th first-class game -- more than half of which have been with European clubs Ulster, Gloucester and Bristol -- Afoa said he jumped at the chance to play for the Crusaders.

"When the call came, it doesn't matter if it's the Crusaders or the Blues, I was just keen to come home and play in front of New Zealanders and my family," he told broadcaster Sky Sport.

"The last couple of days have been a bit of a whirlwind but it's been amazing. I don't have many moons left in my career, this is probably the last year of my career."

David Havili was among the first-half try-scorers as the Crusaders pulled 28-8 clear, but the All Blacks midfielder limped off late in the game with a hamstring injury.

Adding to the team's mounting medical list were knee injuries to loose forwards Cullen Grace and Christian Lio-Willie.

Earlier on Saturday, last-placed Moana Pasifika narrowly missed securing their first win of the season, going down 47-46 to Fijian Drua in Lautoka.

Moana fly-half Christian Leali'ifano missed an 80th-minute conversion attempt, to gift the Drua their fifth win and lift them to 10th on the ladder.

It leaves the Fijian side needing to beat the Queensland Reds next week to have any chance of qualifying for the top eight for the first time.

Both teams scored seven tries in a spectacular contest, with Drua centre Iosefo Masi bagging a hat-trick.

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