Coventry led at half-time when Carl Baker slotted home from the spot a minute before the break after Harlee Dean had pushed Richard Wood in the back.
The Bees were level a minute after half-time however. Clayton Donaldson shrugged off Wood before crossing for Harry Forrester, who swept low into the corner.
Bees goalkeeper Simon Moore was forced into a great save in the 23rd minute when City striker Callum Wilson headed Cyrus Christie's right-wing cross at goal.
Dean then backed up his goalkeeper with two vital clearances, first from Wilson then from Steven Jennings.
Donaldson came close to giving the visitors the lead 10 minutes later, but his lobbed effort bounced wide after beating the goalkeeper.
The Brentford striker missed a great chance to snatch the points in the final minute, slicing wide from close range, as the Bees slipped five points behind the top two, albeit with games in hand.