Johnston off the bench to rescue Celtic again as Dundee's resistance is broken 

Canadian defender scores his second in four days as Belgian newcomer Arne Engels adds a second from the penalty spot 

MAPLE LEAF IT TO ME: Celtic's Alistair Johnston celebrates scoring their side's first goal of the game during the William Hill Premiership match at Celtic Park, Glasgow. Pic: Andrew Milligan/PA Wire

Celtic 2 Dundee 0

Celtic full-back Alistair Johnston came off the bench to break Dundee's resistance with his second goal in four days.