Key Points:

The New Zealand Warriors kept alive their National Rugby League playoffs hopes and gave a stirring home farewell to departing players Ruben Wiki, Logan Swann and Wairangi Koopu with a 42-20 win over Penrith today.

But the seven tries-to-four win was tarnished by an allegation that Warriors fullback Wade McKinnon spat at a touch judge, who had declined to rule a forward pass by the Panthers, allowing winger Luke Rooney a controversial try early in the second half.

Television replays indicated that McKinnon spat after launching a verbal tirade against the touch judge, who was running to the goalposts for the conversion attempt.

It was unclear how close the spit got to the official.

McKinnon was placed on report by referee Ben Cummins, leaving the Warriors a nervous few days over his fate, with the last round before the finals being played next weekend.

The Warriors need to win their last match against the Parramatta Eels to gain a place in the final eight and may need other results to go their way.

They were slow out of the blocks today, with Rooney scoring an early try for the Panthers, but once they settled they dominated possession with their big forwards tormenting the Penrith defence.

They surged midway through the first half, with Manu Vatuvei barging over for a try after a Michael Witt bomb and then sprinting over for a try after an expert offload from skipper Steve Price ignited a combined attack by forwards and backs.

With Ian Henderson creating havoc around the ruck, the Warriors built a solid lead with tries to Micheal Luck, Wade McKinnon and Witt, who was in irresistible goalkicking form with seven goals from seven attempts in the match.

It was 30-4 at halftime and the Panthers scored early in the second half through Michael Gordon.

They followed up with another to Rooney after nine minutes, although the pass to him from fullback Rhys Wesser was clearly forward and resulted in the spitting incident.

It gave Penrith some hope, but the Warriors steadied the ship with tries to Jerome Ropati and a deserving Henderson ending Penrith's finals hopes.

Rooney scored a consolation hat-trick for Penrith.