Crusaders coach Scott Robertson has praised Richie Mo'unga's professionalism after his first-five played a starring role in his side's win over the Blues in the midst of the recent allegations in Cape Town which have resulted in a formal investigation by New Zealand Rugby.

Mo'unga kicked five out of six shots at goal in the 19-11 victory in Christchurch and navigated his team around a wet pitch in his usual serene way despite the media furore which greeted him and his team on arrival from South Africa only a few days earlier.

Accused of spitting beer and pinching a woman's backside in a bar, which Mo'unga and the Crusaders vehemently deny, the 25-year-old was backed by Robertson to do his job despite the distractions and he did so superbly.

Mo'unga's final penalty with three minutes remaining took the game away from the Blues once and for all and denied them a losing bonus point.

Advertisement

"Richie was exceptional," Robertson said. "That kick at the end - he was nice and calm and clear and chipped it through. I'm really pleased for him. He had some amazing moments.

"He's a special player and it shows how professional he is and how he can clear his head from a lot of the clutter that has been on and around him during the week. It just shows he's a class act."

Mo'unga also showed his tactical kicking skills on a wet and cold night not suited to expansive rugby – both sides scored a try each – and nearly scored a remarkable individual try in the second half which was ruled out by referee Mike Fraser and his assistants, a decision not without controversy.

Chasing a high kick, Mo'unga plucked the ball out of opposite Harry Plummer's hands and scampered for the left corner.

Richie Mo'unga and George Bridge of the Crusaders (L-R) celebrate during the round 15 Super Rugby match between the Crusaders and the Blues. Photo / Getty Images.
Richie Mo'unga and George Bridge of the Crusaders (L-R) celebrate during the round 15 Super Rugby match between the Crusaders and the Blues. Photo / Getty Images.

It appeared his pace would get him there but for fullback Melani Nanai's tackle which appeared high – Nanai's right arm slipped up from the shoulder area and made contact with Mo'unga's head, but Fraser and television match official Aaron Paterson ruled it as legal and that the Crusaders playmaker had knocked the ball on rather than ground it on the line.

A high tackle would have resulted in a penalty try – captain Sam Whitelock was vocal in his appeal for one - and a yellow card for Nanai.

Robertson described it as a "pinnacle decision" by the officials and appeared confused by the ruling, although he didn't press the point.

"He touched his head," Robertson said of Nanai. "They made the call. I just talked to [referees boss] Lyndon Bray again this week and we got all the information through from World Rugby about head-high protocols… they looked at it enough times to probably make the right call their end."

The Crusaders' victory means the defending champions need only win one of their final two regular season matches against the Chiefs in Suva next weekend or Rebels in Christchurch the following week to guarantee they will finish as top qualifiers.

They got the result they wanted at the end of a tough week and were planning on celebrating accordingly before flying to Suva on Wednesday.

"We're looking forward to singing our team song," Robertson said. "Richie wrote it so it will be special singing it alongside him."