Having won their last four matches, Mexico were expected to comfortably overcome 106th-ranked Belarus at the Borisov Arena.
But Miguel Herrera's men were on the receiving end of a surprise defeat at the hands of their plucky hosts, who have claimed just one point from their opening four Euro 2016 qualifiers.
Atletico Madrid striker Raul Jimenez twice put Mexico ahead, but Syarhey Kislyak fired home an initial equaliser after Ihar Stasevich's missed penalty and Nikolay Signevich headed a second Belarus goal from close range.
Mexico's improvement continued after the break and they took the lead in the 47th minute, Jimenez controlling the ball on his chest and prodding past Chernik after collecting a wonderfully deft chip from Jonathan dos Santos.
Yet Belarus were back level within three minutes. Paul Aguilar was punished for a foul on Kislyak, who then fired home a rebound after Stasevich's penalty had been parried on to a post by Alfredo Talavera.
The breathtaking start to the half continued as Mexico moved back ahead in the 53rd minute, Jimenez coolly slotting home Giovani dos Santos' cross from the right, only for Belarus to strike back again when Signevich converted Anton Putsila's powerful cross two minutes later.
But the miss did not prove costly as Aleksievich's deflected shot fell into the path of Nekhajchik, who calmly guided the ball into the bottom right-hand corner.
