Saudi Arabia's hopes of securing an automatic berth at next year's World Cup finals in Russia suffered a severe blow on Tuesday evening as Bert van Marwijk's side were handed a 2-1 defeat by the United Arab Emirates.
Goals from Ali Mabkhout and former Asian Player of the Year Ahmed Khalil earned the UAE all three points and kept their own slim hopes of appearing in Russia alive, despite the absence of star player Omar Abdulrahman through injury.
Saudi Arabia remain in second place in Group B of Asia's qualifying tournament for Russia 2018, one point behind Japan and level with Australia, with that pair meeting in Saitama Stadium on Thursday evening.
The top two teams in the group advance directly to the finals, while the team in third will enter into a series of playoffs.
The UAE, meanwhile, have closed the gap between themselves and Saudi Arabia to just three points, although they remain in fourth place in the group with 13 points from their nine games so far and have an inferior goal difference.
With one game remaining for both teams -- Saudi Arabia host Japan on Sept. 5 while the UAE travel to Jordan to take on Iraq -- the chances of Edgardo Bauza's team advancing remain slight.
The Argentine coach's team went into the game without talismanic midfielder Abdulrahman after injury ruled out the Al Ain star and, as the home side struggled to find their rhythm, it was the Saudis who controlled the opening exchanges.
It came as little surprise when the visitors took the lead, with Nawaf Al Abed scoring from the spot in the 20th minute after he had been upended in the area by Mohammed Fawzi.
Just a minute later the UAE were level thanks to a piece of individual brilliance from Mabkhout, who plucked the ball out of the air with his back heel before turning to fire past Abdullah Al Maiouf.
Mohammed Al Sahlawi threatened on several occasions as the half wore on, but it was not until the eighth minute of the second half that the Saudis looked like scoring again.
Osama Hawsawi's header came back off the crossbar following a corner while Al Abed steered his headed effort just wide of the target soon after.
On the hour mark, though, the UAE took the lead with another fine individual effort, this time from Khalil, who picked the ball up more than 35 yards from goal before hitting a ferocious shot on the run that flew high into Al Maiouf's net.
The Saudis threw on veteran striker Nasser Al Shamrani in an attempt to turn the tide back in their favour but, despite Mahmoud Khamis' late sending off for a second bookable offence, the UAE were able to hold on to keep their dreams -- however remote -- of a place in next year's finals alive.