Needing nothing less than a win to keep their slim play-off hopes alive, the Jets delivered with an up-tempo, committed performance.

Roy O'Donovan scored the decisive goal in the 29^th minute with a glancing header from a pinpoint Jason Hoffman cross.

The goal was the Irishman's fourth and most important since arriving back in Newcastle from Brisbane for round 18 and 10^th for the campaign.

Western United weren't without their chances, but were foiled by desperate defending from the home side.

The victory was the Jets' third in four games and moved them into seventh place on 31 points.

Perth and Adelaide are in fifth and sixth spots on 34 points.

The Jets can climb to 34 points with a win over Wellington Phoenix in their final game on August 13.

They would still need a lot to go their way, but significantly they are still alive.

"I have said it before and I'll keep repeating myself, it is out of our hands," Jets coach Carl Robinson said. "If people and teams take care of their own business, then we're not in the equation. What we have to do is take care of our own business. And we did tonight against a very good team. The first goal was always going to be crucial and we got that.

"We got 60 to 70 per cent right and 30 per cent wrong. Last week we didn't score a goal after beating Sydney. Today we scored one and we probably should have scored two or three. When you leave a team hanging around, who have got quality ... they can hurt you. We made it more nervous than we needed to."

Western United coach Mark Rudan, while giving the Jets credit for the win, was adamant that O'Donovan should have been sent off before he scored what proved the winner.

O'Donovan collided with Western United captain Andrew Durante from behind when competing for possession in the 14th minute and Rudan accused the Irishman of using his elbow. Referee Alex King ruled play-on.

"I always thought it was going to be a really good contest and it ended up being that," Rudan said. "I always thought that one goal would decide the game and Newcastle scored - and I take no pleasure in saying this - from a player who should never have been on the park.

"I like Roy. Off the park, I think he is a really good guy but on the park he has a history of doing things like that. I think it was clear as day. We all jumped off the bench and I don't think it is part of the rules. You can't elbow someone off the ball."

Robinson didn't get a good view of the incident which happened near the United penalty box.

"There is a fine line between playing aggressive, because football is a contact sport, but also too many times I think my team are too honest and there is contact with them and they stay on their feet. Then you see other players with minimal contact go over and win a freekick. With Roy, if he has put an elbow in I'll speak to him, if he hasn't then it is part and parcel of football contact."

Hoffman came in for Matt Millar (hamstring) in the only change as coach Carl Robinson kept faith in the XI which dominated the Mariners everywhere bar the scoreboard.

Western United were unchanged from the side which accounted for Melbourne Victory 2-1.

Hoffman was a like-for-like replacement for Millar and the veteran set up the Jets' first opportunity in the second minute with an overlapping run down the right. He delivered the ball into the box but it didn't quite fall for Roy O'Donovan.

There was no doubting the home side's intent.

They looked to get the ball forward early, with balls through the middle to the feet of Bernie Ibini or piercing diagonal passes to Nick Fitzgerald and O'Donovan.

But it was the visitors who nearly struck first when Alessandro Diamanti swooped on a loose pass in the 18th minute but his angled effort took a deflection off Nigel Boogaard and thudded into the right post.

In an end-to-end contest of high quality, Ibini headed just wide from a Fitzgerald freekick into the box.

The game got the goal it deserved in the 27^th minute and it was the home side who went ahead.

Ibini released Hoffman down the right and he curled a first-time cross for O'Donovan, who got in front of Andrew Durante and glanced a header into the left corner.

Western United thought they had equalised five minutes later when a Besart Berisha volley found the back of the net but the Kosovar striker was flagged for offside.

O'Donovan nearly had a double on the stroke of half time when he beat Filip Kurto but not the right post with a left-foot shot.

Hoffman missed a golden chance to double the Jets lead two minutes after the break when left unmarked but he blazed a free header over the bar.

Abdiel Arroyo was introduced for Fitzgerald on the hour and nearly scored with his first touch, hitting a rocket which fizzed past the right post.