United led by four points at half-time, but the Wildcats went on an 11-0 run to start the third quarter to set up the win in front of 12,490 fans at RAC Arena.

Cotton, the league's leading scorer, finished with just 10 points on 4-of-16 shooting from the field.

He made none of his nine three-point attempts.

Terrico White (19 points), Angus Brandt (14), Nick Kay (10), and Jesse Wagstaff (10) helped pick up the slack in an even team display.

Casper Ware top-scored for Melbourne with 19 points, but Chris Goulding (15) and DJ Kennedy (11) were the only other players in double figures

Game two of the best-of-five series will be played in Melbourne on Sunday.

"I thought it was an outstanding second half," Wildcats coach Trevor Gleeson said.

"It was tough, play-off basketball. Physical. It was what you'd expect from a final.

"We had some really good looks in the first half, and we just didn't make them.

"And the second half we got some good looks too, and Jesse got hot there to get us back into the game, and Terrico was outstanding again."

United coach Dean Vickerman rued his side's poor start to the second half, but was pleased with the shutdown job on Cotton.

"I thought our plan on Cotton was solid, and we did a really good job," Vickerman said.

"Casper had the ability to bust through screens and limit Cotton's effectiveness."

Both sides struggled to find their range in a wayward opening term, with the Wildcats heading to the break with a 14-13 edge.

It was the lowest scoring opening term of the season.

United big man Kennedy looked fragile at the free-throw line, missing all four of his attempts in the first quarter.

But he was proving to be a powerhouse in the paint, with his eight points helping United open up a five-point lead during the second quarter.

But with just three minutes left in the half Kennedy had to be helped off the court after copping a shoulder to the jaw when he cannoned into Angus Brandt's screen.

A late three pointer from sharpshooter Goulding gave United a 33-29 lead at half-time.

But the shooting stats weren't pretty from both sides.

The Wildcats made just 2-of-14 three-point attempts, while United (3-of-14) fared only slightly better.

Kennedy was able to return early in the third term, but he was powerless to stop a Wildcats onslaught as the home set up a match-winning lead.

Australian Associated Press