The two-time defending champions overcame a slow start to make a real statement against the league frontrunners in Wednesday's clash at John Cain Arena to pull within two games of top spot on the ladder.

The Wildcats outscored Melbourne 34-17 in the second quarter then played the rest of the match on their terms and with two more meetings in Perth to come, the result sets up an enticing battle as both sides fight to lock in home-court advantage for next month's play-offs.

Melbourne made a charge late in the third quarter to close the gap to nine points but paid the price for a litany of sloppy turnovers while Perth's dominance on the offensive boards (16-8) resulted in 18 damaging points from second-chance opportunities.

Having recorded a double-double against every other NBL team in his debut season, Perth big man John Mooney broke through against United with a 30-point, 14-rebound masterclass while Bryce Cotton (16 points, 10 assists) also played a critical role in the victory.

"(Mooney) just goes to work every possession and there's a good combination with him and Bryce feeding off each other and getting separation," coach Trevor Gleeson said about the 206cm American import's impact with the Wildcats.

"We knew he had the rebounding game and his offensive game just keeps developing - he's been a real big threat out there and the guys are trusting him, giving him the ball at key moments."

United led 19-12 after one quarter but Perth's reserve unit played with greater energy and urgency as they cashed in on United's early foul trouble and poor decision making to turn a seven-point deficit into a 46-36 halftime lead.

"We were really sloppy with the basketball ... we gifted them a lot of points and again they capitalised with their offensive rebounding," coach Dean Vickerman said about his side's performance in the second quarter.

"We put them on the foul line quickly, a lot of early fouls and that allowed them to disrupt us up the floor...credit to Perth, they did a good job with it."

The match looked over with Perth holding a 66-47 advantage late in the third quarter but Melbourne closed the term with nine consecutive points to revive hopes of extending their franchise-record win streak to 12 games.

But United could not produce enough offence to make a run in the final quarter, Jock Landale leading the team in scoring on his return from a minor knee injury with 11 points - the lowest points total for a leading scorer in United's franchise history.

Australian Associated Press