Sydney Roosters finally have a cornerstone win for their NRL season – a 22-10 defeat of premiers North Queensland that coach Trent Robinson says is vital for their 2017 campaign.

And it’s a loss that has put a top-four finish for the Cowboys in grave doubt.

Led upfront by Jared Waerea-Hargreaves and Boyd Cordner on Sunday at Allianz Stadium, halves Mitchell Pearce and Connor Watson steered the Roosters to their fifth victory of the year.

In the process, the Roosters handed the struggling Cowboys their third successive defeat just a month out from the finals.

“It was our best performance of the year so far,” Robinson said.

“There was a lot of arm-wrestle footy. We went to-to-toe with them and we just haven’t been able to do enough this year.”

Three-time successive minor premiers, the Roosters will miss the finals for the first time under Robinson.

“We have struggled to play our best, but they should be proud of how they played today,” he said.

“I have had a lot of questions about next year but it is about now. That was a really good lesson in footy, how you put a game together. The next year is laid on by what we do now.”

The Cowboys opened the scoring through Ethan Lowe in the eighth minute, but from there the Roosters were the better side for much of the contest.

Ryan Matterson put the home side ahead through a converted try in the 28th minute.

Two more first-half tries to Shaun Kenny-Dowall and Cordner had the Roosters in front 16-4 at the break, but only after a Blake Ferguson try was controversially disallowed by the bunker.

A 40m angled run from Latrell Mitchell with 30 minutes left put the Roosters further ahead, and they had to hold a late Cowboys fightback to claim the four-tries-to-two win.

Kane Linnett’s 64th-minute touchdown was the Cowboys’ only second-half try.

If Canberra beat Melbourne in the final game of round 23 on Monday, the Cowboys will be two wins outside the top four with three rounds to play.

“They played well. They deserved it. They wanted it more than us,” Cowboys coach Paul Green said.

“We were a little bit flat and they had a bit more energy than us. They definitely defended better than us and carried the ball better than us.

“It was a similar story last week.

“We just have to get a bit of confidence back and scrap and fight for a win.”

Green said rake Jake Granville (hand) is still at least two weeks away from playing.

Prop Ben Hannant is also due back from knee surgery in two weeks.