Al-Ahli handed Thailand's Buriram United a 3-0 defeat in the quarter-finals of the Asian Champions League Elite in Jeddah on Saturday, with victory setting up an all-Saudi Pro League semi-final against Al-Hilal next Tuesday.
Strikes from Riyad Mahrez and Galeno gave Al-Ahli a two-goal lead by the sixth minute and Roberto Firmino added the third 15 minutes before the interval to complete a comfortable win at the King Abdullah Sports City Stadium.
Al-Ahli, runners up in 1986 and 2012, will continue their quest for their first continental title against compatriots and four-times champions Al-Hilal, who handed South Korea's Gwangju a 7-0 thrashing on Friday to progress to the last four.
Former Manchester City winger Mahrez put the home side in front after four minutes, showing composure to slide the ball into the bottom corner of Neil Etheridge's goal after being found unmarked on the right by Firmino.
Two minutes later Al-Ahli doubled their advantage when Galeno drove into the penalty area from the left to meet Roger Ibanez's defence-splitting pass from deep and push a clinical finish through the legs of the Buriram United goalkeeper.
In a frantic start, Buriram thought they had been given a lifeline when referee Ahmed Al-Kaf pointed to the spot as Merih Demiral brought Martin Boakye down. The penalty decision was overturned when the Omani consulted the pitchside monitor.
Despite that disappointment, Buriram appeared to have weathered the worst of the Al-Ahli pressure, only to concede a third in the 30th minute.
Mahrez's corner was met by Demiral as he leapt virtually unchallenged on the edge of the six-yard box and Firmino pounced at the far post to push the Turkish defender's header over the line from close range.
Al-Ahli goalkeeper Edouard Mendy was called upon to make a rare save in first-half injury time when he gathered Seksan Ratree's header and, with a comfortable lead, the home side moved into cruise control after the break.
Saudi Arabia is hosting the latter stages of the Asian Champions League Elite with the quarter-finals, semis and final being played in Jeddah.
In the remaining last-eight ties, Saudi side Al-Nassr face Yokohama F Marinos from Japan on Saturday and Al-Sadd of Qatar meet J-League outfit Kawasaki Frontale on Sunday.
The semi-finals will be played on Tuesday and Wednesday with the final on May 3.
