Forced to play their home matches in Malaysia due to security concerns, Syria had fallen behind when Robbie Kruse tapped in from close range in the first half but the underdogs refused to buckle to their vastly more experienced opponents.
After looking second best for the first hour, Syria threw caution to the wind as the match progressed and were rewarded for their industry with a result that will give them confidence ahead of next week's second leg in Sydney.
Al Somah had hit the post with a header, that bounced back into keeper Mathew Ryan's hands, in the 77th minute but the Al-Ahli striker was not to be denied from the spot after the referee deemed he had been pushed by Mathew Leckie in the area.
Both sides then went close to scoring winning goals in a dramatic finale but the draw was a fair result that leaves the tie delicately poised.
Australia took a while to settle in the sparsely populated Hang Jebat Stadium in Melaka but their three-man defence coped well with the Syrian strikers and Aaron Mooy pulled the strings in midfield to give the visitors a cutting edge.
Socceroos coach Ange Postecoglou surprisingly ditched his preferred passing game, instead deploying Huddersfield playmaker Mooy in a quarterback role, his long balls over the top causing panic in the Syria defence, especially down the right.
Australia midfielder Mark Milligan was the first to go close in the 19th minute when his long-range effort was palmed wide by a sprawling Ibrahim Alma, and Leckie should have done better when he blasted over from close range five minutes later.
Syria finally got into the contest in the 34th minute when the imposing Al Somah broke well down the right to cross for Omar Khribin but his fellow forward hooked the ball wide from close range with Ryan well beaten.
The duo combined again four minutes later as Al-Hilal's Khribin volleyed Al Somah's lofted pass well wide before Australia took control of the match in the 40th minute with an opening goal that was crafted in Germany.
Hertha Berlin winger Leckie was the architect as he worked hard for an opening down the right flank, the 26-year-old cutting back and drilling the ball goal-wards for VfL Bochum's Kruse to tap in from close range.
Australia started the second half on the front foot and should have doubled their lead in the 48th minute when Tomi Juric broke clear but the Luzern striker was twice denied by the left-hand upright as Syria held on by their fingertips.
The winner of the tie advances to a two-legged inter-continental playoff against the fourth-placed side from the CONCACAF region next month with a berth at next year's World Cup finals in Russia awaiting the victors.
