United were without captain Chris Goulding for Saturday's extra periods, after a knee injury sidelined him late in the fourth term with 29 points next to his name.

He will have scans on Sunday and will be in doubt for Monday's home game against Illawarra, even if he has only jarred his knee.

Scores were tied 84-84 at the end of regulation time after Bryce Cotton's last-second drive failed to drop.

The scoreboard read 89-89 after the first period of overtime, with Melbourne's Casper Ware denied a two-pointer with just one second remaining.

Ware's score was cancelled after he was called for a second offensive foul in 27 seconds.

Melbourne coach Dean Vickerman thought that after being unlucky not to win in regular time, his side didn't play well enough in the extra minutes to grab the win.

"I haven't seen a replay for Casper's drive yet. It looked like there was a fraction of movement there from the defender (Mitch Norton), for me," he said.

"But that was the call that was made.

"I didn't think in the next overtime, with Chris going out, that we executed the way we needed to win the game."

Cotton, with 31 points and Terrico White (27) saw the Cats home, but Angus Brandt will get the credit for the victory.

Brandt's nine rebounds and six points had Perth within one point at the main break.

He finished with 14 points and 20 rebounds, pitted against Melbourne's Josh Boone and Alex Pledger.

Cats coach Trevor Gleeson said he was impressed players stood up in overtime having played (and lost) on Thursday in Brisbane.

"We were pretty tired, with no time to prepare," he said.

"Down the end, it's tough to find a player who wants the ball and score and we're lucky that Bryce is that guy. We also have (White), who is someone who doesn't mind having the ball.

"Some players don't want to take that responsibility and sit back, but he stepped up when we were struggling.

"And (Brandt) just kept the ball alive."

The reigning champions appeared to control the game early and led for most of it.

Goulding looked like blowing the game apart in the third term. When he dropped his 25th point and his fifth from long range, United had a nine-point buffer.

But nine points from Cotton in less than 90 seconds had the home side just two points behind going in to the last term.

Australian Associated Press