It was the last thing any of the 12 remaining golfers out on the Serapong Course wanted to hear as they were locked in battle with the SMBC Singapore Open reaching its climax yesterday.

But moments after the first drops of rain fell over the Sentosa Golf Club, the siren signalling the suspension of play sounded.

Three hours of waiting followed but the thunderstorms overhead did not clear and tournament director Jittisak Tamprasert was forced to declare that further play would be abandoned, dragging the weather-plagued event into a fifth day.

For tournament leader Song Young Han, who was 12 under overall with three holes to complete, the wait will be unbearable.

Said the South Korean, who is seeking his first professional victory: "I am really tired, it has been a long wait.

"Coming back tomorrow is okay for me as the course should be in a better condition (less wet). I played well today, quite steady."

The 24-year-old was one under through his round, mixing two birdies with a bogey, and crucially sinking a couple of testing par putts on back-to-back holes (the 13th & 14th) to maintain his two-shot lead at the US$1 million (S$1.44 million) event.

He returns at 7.30am today to face another examination of his nerves - a 3m putt to save par on the 372m, par-four 16th green.

Besides the US$180,000 winner's cheque, he is also seeking to become the first Korean winner of the Singapore Open and the first Asian to triumph since Jeev Milkha Singh in 2008.

Said Song: "I will just play shot by shot and hope I can get the win.

"I have had a lot of second-place finishes (six in total).

"It is time for a victory."

Championship titles are something world No. 1 Jordan Spieth has become familiar with, after a stellar 2015 in which he won five times, including two Majors.

The 22-year-old American phenomenon fired five birdies - the most of anyone inside the top 13 on the leaderboard - yesterday to put himself in contention and was 10 under overall.

He was on the 496m, par-five 18th green and contemplating a five-foot birdie putt that would have halved Song's lead and applied pressure on the world No. 204 when the horn sounded.

It may have left his agent Jay Danzi - who is also filling in for his injured caddie Michael Greller - scrambling to change flights back home to Dallas in the United States but Spieth shrugged off the minor inconvenience.

He said: "I was due to leave tonight but next week was an off week anyway so we have changed the travel schedule and I will be there early tomorrow to try and finish this off."

Monday finishes have become par for the course at the Singapore Open, with the 2010 and 2011 editions also similarly delayed due to inclement weather.

For China's Liang Wenchong, 37, who finished joint 10th in 2010, it was a case of deja vu on several fronts.

He was runner-up by a single stroke to Ian Poulter in 2009, failing to birdie the 18th hole which would have sent him into a play-off against the Englishman.

A closing two-under 69 yesterday left the Chinese on 10-under 274 and the clubhouse leader but it could have been a lower score had the Zhongshan native not missed a birdie putt from four feet on the 496m, par-five final hole.

He said: "I missed several makeable birdie opportunities and I'm regretting it now."

His last stroke was tinged with heartbreak. But Spieth and Song had to wait another night before delivering their final act.