The Jeddah club, runners-up in 1986 and 2012, triumphed at their King Abdullah Sports City Stadium thanks to two goals in seven minutes towards the end of the first half from Brazilian Galeno and Ivory Coast captain Franck Kessie.
The Asian Champions League’s latter stages have all taken place in Jeddah.
With the win, Roberto Firmino, Edouard Mendy and Riyad Mahrez become the first players to capture both Asian club football’s premier title and its European equivalent.
The trio won the Champions League with Liverpool, Chelsea and Manchester City.
Al Ahli, who are majority-owned by Saudi Arabia’s Public Investment Fund, are awarded US$10 million for clinching the title.
Matthias Jaissle’s side went unbeaten through all 13 matches of the campaign.
Frontale, meanwhile, were contesting the final for the first time, having never previously been beyond the last eight.
Al Ahli began on the front foot, summer signing Ivan Toney stinging the palms of Louis Yamaguchi on five minutes before the Frontale goalkeeper then saved Ziyad Al Hosani’s close-range effort from the resultant corner.
At the other end, Frontale’s Brazilian forward Marcinho showed some fast feet down his side’s left, before sending his effort inches past Edouard Mendy’s far post.
Yet Al Ahli always looked the more dangerous. Toney lashed wide on the half-volley, defender Roger Ibanez curled narrowly off target, and Firmino sent a volley straight at Yamaguchi.
However, on 35 minutes, Firmino rolled a pass to winger Galeno, who curled a spectacular effort from 25 yards into the top corner.
Galeno, a winter signing from Porto for a reported 50 million euros (US$56 million), has actually taken Firmino’s spot in Al Ahli’s Saudi Pro League squad, meaning the former Liverpool forward is not registered to play in the domestic league.
Three minutes before half-time, Firmino floated a cross into the Frontale six-yard box for Kessie to power home his header and double Al Ahli’s advantage.
The assist lifted Firmino, the club captain, to seven in this season’s Champions League – and to one behind Mahrez at the top of the tournament’s assist charts.
Frontale, who defeated Cristiano Ronaldo’s Al Nassr in the semi-final, did not have a shot on target in the opening 45 minutes.
In the second half, Firmino and Mahrez each flashed efforts well wide, with the former substituted on 74 minutes to rapturous applause.
Not long after, Frontale substitute Tatsuya Ito fired two shots in quick succession, inches off target.
In the end, Al Ahli celebrated becoming only the third Saudi club to win the Champions League, after record four-time winners Al Hilal and two-time champions Al Ittihad. (AFP)
