The Kings looked cooked on Saturday night when they trailed 78-62 with little more than six-and-a-half minutes to go, but a 24-2 run from that point secured an improbable win.

Sydney ratcheted up their defensive pressure down the stretch and United, who dominated most of the game to that point, couldn't execute under pressure.

Brazilian Didi Louzada nailed a clutch three-point attempt to give the Kings the lead with just over 40 seconds left and former United guard Casper Ware iced the win with another basket.

Roared on by the majority of a crowd of 13,103 - the club's fourth highest home attendance - Sydney secured their first win in five playoff games stretching back to 2008.

Sydney led for only just over three and a half minutes of the game but coach Will Weaver said he never doubted his players and it was their efforts rather than any tactical ploy by him that turned the game around.

"I stayed out of the way when my players were doing what they were doing in that 24-2 run," Weaver said.

"Everyone wants to write a story about something gets done.

"Often the answer is to lay back and trust the players are in position and in the right kind of headspace to do what's called for."

Sydney ratcheted up their defensive pressure down the stretch and United, who dominated most of the game to that point, couldn't execute under pressure.

The always energetic Jae'Sean Tate scored 24 points and Brad Newley 17 for the Kings.

Ware, who averaged almost 29 points a game in the regular-season games against Melbourne, had a difficult night before having the last laugh.

He missed his first eight field goals and didn't score a point until well into the third quarter, before finishing with seven.

Kings centre Andrew Bogut scored only three points, but contributed ten board and three blocks.

Guard Melo Trimble, who replaced Ware at United, scored 34 and centre Shawn Long 23, but no other United player contributed more than eight as their team slumped to a fourth-straight loss to Sydney.

Both sides shot under 30 per cent from long range with Melbourne taking eight more three-point attempts than they did two-point shots.

Like Ware, in-form Melbourne captain Chris Goulding contributed just eight points, missing seven of last eight long bombs after opening the game's scoring with a three.

Sydney benefited from the energy of veteran Newley and Louzada, who is attached to NBA club New Orleans and whose president David Griffin was present at Saturday's game.

"We thought what changed the game was the pace that they started to really push," Unjted coach Dean Vickerman said.

"I thought Newley was a factor in changing the pace of the game the way that he was attacking and I thought for the last five minutes, we probably slowed our attack to get started on our offence and we saw a few late shot clock situations as well, so we can be better at that."

Game two will be played on Monday in Melbourne.

Australian Associated Press