Worst pass in NRL history?

One of the biggest howlers in NRL history has helped send the Brisbane Broncos through to the NRL grand final.

Kiwis centre Shaun Kenny-Dowall had a mind explosion in the first minute of his Sydney Roosters side's preliminary final clash with the Broncos, throwing a woeful intercept which kick-started Brisbane's impressive win.

The Roosters winger's mistake was one that proved incredibly costly as it provided the platform for the Broncos to win 31-12 in front of a packed Suncorp Stadium crowd in the first preliminary final.

Having recovered a kick and looking to launch the Roosters' very first set inside the game's opening minute, Kenny-Dowall let loose with a long inside ball intentioned for fullback Roger Tuivasa-Sheck.

But Darius Boyd, who was pushing up to close off an option he never thought Kenny-Dowall would actually use, was able read the arc of the pass, switched on his afterburners, intercepted the ball and ran away to score under the posts.

Only the wrapping paper and ribbon were missing from what was a most unexpected gift from Kenny-Dowall - and its recipient was still coming to terms with the fact it all actually happened in the sheds after the match.

Boyd says he doesn't know what was going through Kenny-Dowall's head when delivered the errant pass that set Brisbane on course for the grand final.

"I don't know what Kenny-Dowall was thinking to be honest," Boyd said.

"I was pushing up in the hope he wouldn't pass and then when he did I thought I'm a chance.

"I got closer and closer... I was pretty shocked. I think I'm still shocked."

There were still 78 minutes for the Roosters to repair the damage but it was a moment they were never able to recover from, as the Broncos soon stretched out to a 14-0 lead.

"It's a tough road, it's a long season. Sometimes you need a bit of luck and for things to go your way," Boyd said.

"We had a few bounces of the ball that went our way tonight, but we've had a great year, I think we deserve it."

Roosters five-eighth James Maloney said nobody will be blaming Kenny-Dowall for the loss.

"There's definitely no hard feelings towards anyone," he said.

"We're a group, we're all in it together and we weren't good enough tonight.

"I don't know how many points they ended up on but there's a lot more that could have been stopped."

The Broncos will face either Melbourne or North Queensland in next Sunday's NRL grand final, to be played at ANZ Stadium.

- AAP