A dominant performance from the Hoops saw they win comprehensively thanks to the two former Dundee United players.
Celtic had all the early pressure and took the lead on eight minutes after Leigh Griffiths blocked shot found its way to Gary Mackay-Steven who slotted the ball under the St Johnstone ‘keeper.
The lead didn’t last long however as the Saints levelled three minutes later through Steven MacLean after turning home Michael O’Halloran’s cross.
Jozo Simunovic could have prevented the goal however his slack defending allowed the former Hoops player to get past him too easily.
Another former Dundee United player got on the scoresheet for Celtic as captain Mikael Lustig found Stuart Armstrong.
The midfielder rushed on to meet the cross and smashed the ball on the volley into the back on the net giving Mannus no chance.
Stefan Johansen picked out Mackay-Steven who scored his second of the game to put clear daylight between the teams.
Here are the player ratings from today’s 3-1 win at Paradise.