Marc McNulty scored a hat-trick as Coventry City kept their play-off destiny in their own hands with a thumping 6-1 win at Cheltenham Town.Lee Burge parried a shot from Mohamed Eisa in the ninth minute, but Coventry soon took complete control.Tom Bayliss scored the first after a neat free-kick ended with Jordan Shipley supplying the cross that was well finished in the 11th minute.McNulty headed in the second from a Jack Grimmer cross in the 27th minute.A low ball in from Maxime Biamou was dummied by McNulty and Shipley fired in to make it 3-0 in the 38th minute.It was 4-0 two minutes before half-time as McNulty lifted the ball over goalkeeper Scott Flinders after Jordan Willis' ball forward.Cheltenham pulled one back in the 58th minute from a penalty after Eisa was brought down by Burge.Eisa converted from the spot for his 23rd League Two goal of the season.But Biamou's stunning overhead kick from McNulty's cross made it 5-1 in the 74th minute and McNulty completed his hat-trick with another fine finish four minutes later.