Coming off the bench for a cameo appearance in the last 20 minutes, Culina smashed a 30-metre drive into the back of the net with two minutes remaining after Steve Fitzsimmons' cross was only half cleared by the home defence.

The game had been postponed for 24 hours after the team's private jet was delayed in Port Headland as engineers waited for a maintenance part to be transported from Perth.

But it was worth the wait for United coach Miron Bleiberg who paired strikers Shane Smeltz and Joel Porter together for the first time since Porter joined the club from English side Hartlepool.

Matt Osman and Daniel Piorkowski both started and Jess Vanstrattan continued in goal as his quest for match sharpness gathered pace, although he was merely a spectator for much of this outing as United dominated on a warm, balmy night at Hougang Stadium.

Bleiberg's men started well and controlled possession from the opening whistle with Zenon Caravella his usual busy self in midfield and young gun Tahj Minniecon looking menacing in his role behind Porter and Smeltz.

The Smeltz/Porter combination showed early signs of a promising future as the duo linked well several times to threaten the Singapore goal.

Their bright opening was rewarded in the 27th minute when Porter's cross was turned into his own net by Abdil Qalyyim, who succumbed to pressure from the lurking Smeltz. The same player was later shown the first caution of the game after flooring Matt Osman with a heavy challenge.

Eight minutes later Osman's free-kick from the right hand side was met forcefully by the head of Michael Thwaite who powered home to make it two goals in two games for the former Melbourne Victory man.

The visitors were rarely in danger during the first period thanks to another dominant defensive performance from Dutch import Bas Van Den Brink, ably supported by the classy Adam Griffiths.

On the stroke of half-time Smeltz almost added a third with a curling 25-metre free-kick that sneaked just past the upright, and right after the break Zenon Caravella was left frustrated when his header form Porter's cross rebounded back off the crossbar.

However, it only took United until the 51st minute to confirm their dominance thanks to the ever-dangerous Porter. Osman's deep corner was met by Thwaite whose effort came back off the post, but the United vice-captain rallied to clip a far post cross towards the unmarked Porter who made no mistake with his well placed header.

Culina entered the fray in the 67th minute when he replaced Steve Pantelidis. The Socceroo midfielder's class was evident immediately as his darting runs and clever use of the ball caused further grief for the home defence as United pressed for more goals.

His stinging low drive that left Singapore ‘keeper Jasper Chan helpless as it flew into the net, was a fitting introduction for Culina as he wore the gold and blue of United for the first time.

Following the emphatic win, Miron Bleiberg's men left for Hong Kong directly after the game to prepare for their hit-out against Hong Kong FC on Friday evening, the final game in their two-match stint in Asia.

(Qalyyim [og] 27', Thwaite 35', Porter 51', Culina 88')

1.Jess VANSTRATTAN, 3.Michael THWAITE (Kristian Rees 62'), 13.Bas VAN DEN BRINK, 2.Steve PANTELIDIS (Jason Culina 67'), 4.Daniel PIORKOWSKI, 6.Adam GRIFFITHS (Richard Greer 80'), 17.Matt OSMAN (Ben Wearing 88'), 7.Zenon CARAVELLA, 15.Tahj MINNIECON (Steve Fitzsimmons 38'), 14.Joel PORTER (Gol Gol Mebrahtu 57'), 9.Shane SMELTZ (Andrew Barisic 57').

Subs not used: 20.Scott HIGGINS, 20.Jerrad TYSON (gk, yth).