Saudi Arabia mounted their first attack in the 10th minute, as Mohamed Kanno brought down a long pass well, but his shot was off target.
Saudi Arabia created their best chance of the first half in stoppage time. Ali Alhassan got on the ball whipped in from the right but his header went wide.
Mexico broke the deadlock at the beginning of the second half. A corner was flicked on and Henry Martin was there to bundle the ball into the back of the net in the 47th minute. Five minutes later, Luis Chavez's free kick from 30 yards out flew into the top corner.
Two goals in quick succession put Mexico back in contention for qualifying from Group C, and one more goal would allow them to overtake Poland in second place as Argentina led Poland 2-0 meanwhile in the other game.
Orbelin Pineda found space on the edge of the box but his shot went just wide of the post in the 78th minute. Uriel Antuna had a goal disallowed for offside in the 88th minute.
In the injury time of the second half, Salem Aldawsari scored for Saudi Arabia with a right-footed shot from the center of the box.
Despite this win, Mexico still couldn't qualify for the round of 16 on goal difference. It's the first time that Mexico have failed to reach the World Cup knockout stage since 1978, while Saudi Arabia have never progressed through the group stage since 1994.