A defiant display from Tony Popovic's side, that was highlighted by a remarkable late save by Ante Covic to maintain another clean sheet, secured a remarkable success for the A-League side in its first crack at the competition.
In just their third season of football, the Wanderers lifted the trophy after Tomi Juric's goal in the first leg at Parramatta last weekend proved the difference between the teams after 180 enthralling minutes.
"To come such a long way in the short history of this club and win a title like this ... I'm so proud. Tonight is very special and it's not going to be forgotten," Wanderers goalkeeper Covics said.
A delighted Popovic said the game was everything you'd expect from a final.
"It was difficult, they're a very good team, they had fantastic support," he said.
The Wanderers barely had a sight of goal on Sunday and had to repel wave after wave of attacks from their Saudi opponent at a hostile King Fahd International Stadium.
Wanderers needed more than just a stroke of good fortune to emerge unscathed, as referee Yuichi Nishimura turned down strong appeals for at least three seemingly blatent penalties for the host.
Covic was the hero for the visitor, the Wanderers veteran pulling off several important saves, but none more so than his 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's free-kick with the goal gaping.
That set the tone for a night of frustration as far as the home side was 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 it went one better than Adelaide United's defeat in the 2008 showpiece.
The win sealed a spot in the 2014 FIFA Club World Cup (CWC) for the Wanderers next month in Morocco and some $2 million in prizemoney.
The Wanderers will face CONCACAF qualifier Cruz Azul of Mexico in the CWC quarter-final on 14 December (AEDT) with the victor rewarded with a showdown against European champion Real Madrid three days later.
"It's a special group to coach. They've made history. It will sink in in a few days," Popovic said.
"I'm very proud of the players. Marvelous achievement for the players, club and Australian football."
That the Wanderers were able to grind out a result was made more impressive by the ferocious environment.
Lasers continually shone in Covic's eyes, the crowd becoming more restless as the match wore on.
But Western Sydney held out, prevailing where Adelaide United could not.
The result is especially sweet for Popovic's side, denied in two A-League grand finals in its first two attempts.
On the last whistle, both the winners and defeated slumped on the ground, drained of all energy.
That quickly gave way to a release of frustration, with rivals involved in late fisticuffs.