With 12 minutes on the clock, Barnet were awarded a penalty after questionable defending from the hosts. Akinde missed from the spot, but Andy Yiadom was there to convert into an empty net to put the Bees in front.
Akinde could have doubled the lead three minutes later but failed to score despite a gaping goal in front of him.
The visitors continued to dominate in the second half despite not creating any clear chances as the second half went on.
However, N'Gala chose to notch his first goal for the Bees in the most thrilling of circumstances when, with 92 minutes on the clock, he rose the highest to head home and send the away fans into raptures.