But Baptiste unwittingly turned the ball past goalkeeper Paul Rachubka seven minutes from time to leave Ian Holloway's men to rue what might have been.
Rachubka had to be alert inside the opening 50 seconds to deny Coventry's Michael McIndoe, while David Vaughan and Aron Gunnarsson both blazed wide from 20 yards in an otherwise scrappy first 20 minutes.
Sammy Clingan found himself in space just outside the penalty area, but his 18-yard effort cleared the crossbar before Vaughan again tried his luck from distance.
Both sides continued to create and spurn chances at regular intervals as Keith Southern, Leon Best and Bannan all missed the target from 12 yards.
Keiren Westwood then thwarted Ormerod twice in the space of three minutes.
The former Southampton and Preston striker first saw his 20-yard easily dealt with by Westwood before the Republic of Ireland international brilliantly blocked out Ormerod's effort after racing off his line.
Carl Baker flashed a header from McIndoe's cross wide shortly before the interval and the lively Charlie Adam - who has been attracting the interest of Middlesbrough - tested Westwood moments after the restart.
Adam has proved a revelation since moving to Blackpool from Rangers and the Scottish striker went close to breaking the deadlock after 48 minutes as Westwood tipped his 18-yard strike round the post.
Only the crossbar prevented promising Villa youngster Bannan opening his Blackpool account two minutes later from outside the penalty area.
Ormerod was then controversially shown a straight red card for violent conduct after appearing to clash with Coventry midfielder Gunnarsson.
The loss of Ormerod - who has scored six goals this season - should have hampered the visitors, yet Holloway's side continued to press forward as Southern went close.
And all the pressure from the Seasiders paid dividends with 21 minutes remaining as a moment of magic from Bannan opened the scoring.
The 20-year-old - who extended his loan deal at Bloomfield Road until the end of the season on Friday - spotted Westwood off his line and perfectly executed an impressive 30-yard chip into the net.
Bannan's first competitive goal since he scored in March while on loan at Derby prompted a chorus of boos from the disgruntled Ricoh Arena faithful.
Clinton Morrison's weak effort from six yards and a wayward Freddy Eastwood shot from outside the penalty area did little to lift the home fans before a Baptiste own goal while under pressure from Southern following a goalmouth scramble hauled the sides level seven minutes from time.
Gary Taylor-Fletcher and Eastwood both had chances to win the game late on.