They were undone by a late goal last November when they last faced Thailand.
Last night at Nakhon Ratchasima, the Singapore national football team again succumbed late in their match against the same opponents in their international friendly to commemorate 50 years of diplomatic ties between the two countries.
This time, some hapless defending proved to be the Lions' undoing as they leaked two goals in the final four minutes in a 2-0 defeat.
Not only did it ruin a decent performance, but the Lions also missed out on their chance to exact revenge, after seeing the Thais beat them 1-2 at the National Stadium en route to clinching their fourth AFF Suzuki Cup last December.
But unlike last November's loss, which came against Thailand's best team, yesterday's defeat came against a squad made up largely of second-stringers.
Thai coach Kiatisuk Senamuang fielded a new-look starting line-up, with midfielder Prakit Deeprom the only player to have started in the November clash.
On the other hand, Lions coach Bernd Stange made some tactical changes, starting Safuwan Baharudin - currently on loan with Australia's A-League side Melbourne City - in central midfield, while Zulfahmi Arifin was handed a role at centre-back alongside Afiq Yunos.
The changes made little difference, however, with the Thais dominating the encounter from start to finish.
And the Lions suffered a potentially serious blow in the 32nd minute, when Afiq had to be stretchered off the pitch after landing awkwardly on his left ankle after challenging Prakit for the ball in the box.
Hafiz Abu Sujad came on for the injured defender and slotted in at left-back which meant that Shaiful Esah moved to centre-back.
While the makeshift defence held firm initially, Thailand eventually exposed the frailties.
The deadlock was broken in the 88th minute when Suttinun Phukhom ghosted in behind his marker Hariss Harun to head past goalkeeper Izwan Mahbud from a Theerathon Bunmathan free kick.
In stoppage time, Pokkhao Anan found space inside the box and lifted the ball over a charging Izwan to make it 2-0.
Both sides donned black armbands and observed a minute's silence before kick-off, as a mark of respect for former Singapore Prime Minister Lee Kuan Yew, who died on Monday.
Stange has now lost 11 of his 23 games in charge of the Lions, who will next host Guam in an international friendly at the Jalan Besar Stadium on Tuesday.
This article was first published on Mar 27, 2015.
Get a copy of The Straits Times or go to straitstimes.com for more stories.