By PETER JESSUP

If the Roosters had had a spy watching the Warriors' 66-24 win in their last pre-season run against a local Auckland side, he would have gone home with a simple plan to beat them at Ericsson Stadium in the NRL opener.

The Warriors were unstoppable in the opening exchanges at Waitakere Stadium on Saturday.

Monty Betham started a powerful roll from dummy-half and Ali Lauiti'iti was devastating near the line.

As the game opened up, Justin Murphy played a good link-man role after several bursts.

From the bench, utility Brent Webb showed surprising speed to leave everyone behind on four occasions. He scored a hat-trick and was called back once for collecting a forward pass.

The first 40 minutes and the first 10 minutes after the break were great. By then, it was 52-0, and the West Auckland Cowboys did not look as if they could mount an attack, let alone score.

But that Roosters spy would be telling coach Ricky Stuart that the Warriors flagged after that, and a Cowboys side with little more than the chip-through as a plan of attack managed four unanswered tries.

The spy would be telling Stuart that the Roosters need to run hard and fast at the Warriors and take advantage of their slow reaction times. That speed would kill them off in the latter stages.

"It was a bit of an ugly finish," Warriors coach Daniel Anderson said.

But he cites several reasons for being prepared to accept the turnaround in fortunes in the middle of the second session of 25 minutes and for all bar the last few of the final 25 minutes.

The 90-minute game-time was one reason. Then there were the big early lead and declining motivation in 30deg C heat.

Anderson also referred to the fact that he took Betham and Lauiti'iti off at the end of the first 40 minutes and did not run them again. By that stage Iafeta Palea'aesina had twisted his knee and medical staff had given Anderson an early diagnosis that the prop would be gone for three weeks.

Starting with a bench of five against a bench of nine, Anderson reduced his squad to 15 versus 22 during the match.

Justin Morgan, Mark Tookey and Dallas Rennie played more than 60 minutes, and Logan Swann and Sione Faumuina played all 90.

"At the end there were 10 players from our starting 13 [for the Roosters] who weren't on the field," Anderson said.

During that period, he also asked the referee to keep the Warriors back 12m and the Cowboys back eight.

But Anderson said he was not happy with the late scoring flurry from the Cowboys "and neither was the team happy letting them in."

"We have some work to do to defend against kicks."

He will run the Warriors two sessions a day for a total of five hours every day this week.

"I can tidy that up in the next two weeks," he said of their inattention to detail.

* In the curtain-raiser, a rugby team beat a league side 26-22 in a hybrid game mixing the two codes.