Moon Soonho punished the luckless hosts as his 93rd-minute winner deflected off Lau Meng Meng to settle a war of attrition, with goalkeeper Yazid Yasin shining for the away side
The Cheetahs failed to bury any of the golden opportunities they had against the visiting Rams and almost inevitably, fell to a last-gasp goal.
Captain Lau Meng Meng's unfortunate own goal with the last meaningful kick of the game saw Woodlands move into sixth, as Hougang slipped to 10th to make their top-six ambitions more difficult.
The hosts tried to assert their dominance from the start as they tested opposing custodian Yazid Yasin with a couple of tame efforts early on, but neither side were really able to gain a foothold.
In the 17th minute, Moon touched a long ball past onrushing goalkeeper Fadhil Salim in the box, but a covering Hougang defender managed to hook the ball away in time as an empty goal loomed.
Mamadou Diallo had the game’s first clear opening five minutes later after Azhar Sairudin’s cunning through ball left the Guinean with only Yazid to beat. However, the striker blasted his low finish just past the post.
Moon then slammed an effort just wide at the other end after a Woodlands break saw the striker take a Fadhil Noh pass and jink past his marker into the box.
The game was sparking to life by now as Diallo missed another good chance on the half-hour, failing to convert Fazli’s teasing left-wing cross on the counter-attack.
An unmarked Azhar then somehow headed a deep cross wide, with Yazid already looking resigned to his fate.
Taufiq Rahmat replaced Fadhil Noh in an early substitution for the Rams but it did not produce any desired effect it was supposed to as the game fell back into a tepid rhythm and ended goalless at the break.
Hougang coach Johana Johari brought on Jerome Baker at half-time to partner Diallo, with Shahir Hamzah making way as the hosts sought more options in attack.
Diallo wasted yet another chance just four minutes after the restart, heading wide a lovely Nurhilmi Jasni ball at the far post.
It was Taufiq who spurned the next gilt-edged opportunity as he somehow headed Moon’s cross into the ground and over the bar from close range on the half-hour.
The away side were holding firm in defense amid a barrage of crosses as the hosts tried to increase the pressure, with Yazid doing well to claim high balls amongst a sea of bodies.
Woodlands could have stolen the three points six minutes from time when Moon poked a slide-rule pass from substitute Goh Swee Swee agonisingly wide of the near post.
Liam Shotton then wasted a three-on-two break for Hougang in injury time as he screwed a shot wide instead of crossing for either of the other two, as both sides look set for a share of the spoils.
But Moon had other ideas and his perseverance for battling to the right byline was rewarded when his low cross was deflected past Fadhil by Lau Meng Meng into the far corner for an own goal to crush Hougang hearts, as the final whistle sounded moments later.