Celtic have moved into a 2-1 lead against Dundee United following a lively opening 45 minutes at Tannadice Park in the Scottish Premiership.
The champions enjoyed a dominant start to the game, with Griffiths heading the wrong side of the post just two minutes in.
Celtic were then denied by the woodwork just a couple of minutes later as Kris Commons's shot was hooked off the line and onto the crossbar by Mark Durnan.
Ronny Deila's side eventually took a deserved lead on 17 minutes through Griffiths, who broke free of the Dundee defence before rounding goalkeeper Luis Zwick and slotting in.
The Hoops remained dangerous in front of goal after going ahead, but the lively Commons was denied twice in quick succession by Zwick.
Commons's personal battle with the Dundee shotstopper continued towards the end of the half when his powerful volley was kept out before Emilio Izaguirre lashed a long-range drive wide after the hosts had failed to clear their lines from a corner.
Celtic doubled their advantage a minute before the break as Durnan diverted Commons's cross into his own net, but Dundee were handed a lifeline moments later when Chris Erskine converted from the penalty spot following a foul by Efe Ambrose.