Thanks to an impressive debut performance from veteran defender Steve Staunton, City controlled one of the most one-sided matches seen at Highfield Road in recent seasons.
The 34-year old even proved to be one of City's best attacking outlets, crossing for Dele Adebola to head over on 30 minutes, before a rasping 35-yard drive tested James Walker moments later.
Walsall made very little impact on the game until Youssef Safri saw red for the home side with a quarter hour to go.
Paul Merson was relatively subdued for the visitors, though showed how dangerous he can be on 17 minutes with a neat turn on the edge of the box and a brilliant curling shot that crept inches wide.
When McAllister teed up Patrick Suffo after 37 minutes he forced an excellent save from the flawless Walker with a well-struck drive.
Coventry piled on the pressure after the break. Mo Konjic, on a typical foray forward, struck a sweet shot that again Walker was equal to five minutes in.
The Sky Blues were then handed a perfect chance to take the lead when Suffo was brought down in the box by Neil Emblen.
However McAllister's spot-kick cannoned off the inside of the post and back into Walker's arms.
Walsall still posed problems on the break, Scott Shearer was a relieved man when Steve Corica's effort flew past his left-hand post just after the hour mark.
Safri then saw red with 13 minutes left on the clock after picking up a controversial second booking.
The Moroccan, who had been booked for a needless tackle in the first half, seemed to be brought down just inside the box by Zigor Aranalde.
Referee Chris Foy chose to penalise the City player for the dive.