Tomi Juric's goal in the first leg in Parramatta last weekend proved the difference between the teams, sealing an historic 1-0 aggregate victory as Wanderers became the first Australian team to win the continental trophy.
Tony Popovic's team barely had a sight of goal on Saturday and had to repel wave after wave of attacks from their Saudi opponents at a hostile King Fahd International Stadium in Riyadh.
They needed more than just a stroke of good fortune to emerge unscathed, as referee Yuichi Nishimura turned down strong appeals for three seemingly blatent penalties for the hosts.
Ante Covic was the hero for the visitors, the Wanderers' veteran goalkeeper pulling off several important saves, but none more so than a miraculous stop from substitute Yasser Al Qahtani.
Covic somehow tipped the Saudi striker's close-range shot around the post with five minutes to go, as the A-League side held on.
Al-Hilal might have broken Western Sydney's resistance as early as the 19th minute, centre-back Digao failing to get on the end of Thiago Neves' free-kick with the goal gaping.
That set the tone for a night of frustration as far as the home side were concerned.
Refreee Nishimura was at the centre of the action, first turning away strong appeals when Anthony Golec brought down Nawaf Al Abid inside the area with a minute to go in the first half.
The ball then struck the raised arm of Brendon Santalab eight minutes into the second half, before Covic felled Salman Al Faraj in the 65th minute.
Amazingly, the Japanese official - heavily criticised for awarding Brazil the softest of spot-kicks in the opening match of the 2014 World Cup against Croatia - was unmoved on each occasion.
As tension grew, Al-Hilal continued to press and Al Qahtani thought he had given his side a vital goal late on, only for Covic to perform heroics.
That was enough for Wanderers to lift the title, as they went one better than Adelaide United's defeat in the 2008 showpiece.