Al Ahli took an early lead as Ahmed Khalil opened the scoring on 12 minutes before Al Hilal levelled in the 32nd minute through former AFC Player of the Year Yasser Al Qahtani and Radoi scored from the spot in the first minute of stoppage time.
Al Ahli silenced the home crowd when AFC Young Player of the Year Khalil stole the ball from Al Hilal defender Mohammad Al Nakhli before going towards the goal and scoring with a low shot past Mohamad Al Deayea.
The early goal stunned Al Hilal who went onto the attack and started to haul themselves gradually into the game.
Their best chance came on 23 minutes when South Korean Seol Ki Hyeon sent a cross from the right which was headed wide by Al Qahtani.
The pressure from Al Hilal continued and they should have scored a minute later when their Libyan midfielder Tareq El Taib tried his luck from distance but his shot was saved by Al Ahli goalkeeper Obaid Al Tawila.
However, Al Hilal eventually levelled the scores when Seol made his way down the right before crossing for Al Qahtani to score past Al Tawila.
Al Ahli started the second half in the ascendancy and Brazilian striker Bare hit the right post with his shot from outside the area soon after the resumption while Khalil clipped the other upright on the rebound.
At the other end, Seol fired off a left-foot shot which was narrowly wide before Abdulla Al Zori headed just over the bar.
Al Ahli should have taken the lead late in the game when Clederson Cesar came from nowhere to steer a loose ball towards goal but Al Deayea kept the ball out with the best save of the game.
With barely a minute on the clock, Al Hilal were given the chance to take all three points when Al Qahtani was fouled by Mohammad Qassim in the area and Radoi made no mistake.