Asian player-of-the-year Yasser Al Qahtani struck at the end of each half to ensure the three-times Asian champions stayed within reach of runaway leaders Uzbekistan in Group 4.
Lebanon stunned the crowd when they took the lead on 43 minutes through Mahmoud El Ali but Al Qahtani, the golden boot winner at last year’s Asian Cup, answered back on the stroke of halftime to spoil their celebrations.
Osama Hawsawi added another in the 65th minute and Redha Tukar made it three seven minutes from time before Al Qahtani struck for the second time.
The Saudis are second in Group 4 with three games remaining, three points behind Uzbekistan, who annihilated Singapore 7-3.