The Ravens took a two goal lead within the first fifteen minutes. A free header from Alvin Jarvis went under Paul Shepherd who was beaten in the 15th minute when Michael Swan drove from home from the edge of the area.
Just before half-time, Sphinx pulled one back with a penalty. Coalville keeper Chris Gibson took a kick at Jerome Murdock and was red-carded. James Dodd went in goal and his first job was picking the ball out of the net following Casey Caggini's successful conversion of the resulting penalty.
Dodd made a superb save from Murdock in the 49th minute but could do nothing when Robbie Stevenson finished smartly from ten yards in the 65th minute.
Sphinx had a shot cleared off the line in the 75th minute and got away with two good shouts by the visitors for penalties which were not given as an entertaining game finished 2-2.
The second leg is on Tuesday April 1st and the final is at Walsall FC.
Coventry Sphinx Line Up was
Shepherd,Mace,Knibbs,Drennan,Ward (46 Heywood),Winterbottom,Harris (77 Halton),Caggini,Murdock,Stevenson,Maguire (McSheffrey 83) SNU Hooker
Man of the match James Mace Att 73
Other scores Tottenham 4-4 Chelsea, Manchester United 2-0 Bolton.