Callum McGregor added a second after Griffiths opened the scoring at Firhill on Saturday .
Were comfortable despite a late penalty - after Steven Lawless had been fouled by Erik Sviatchenko - from Sean Welsh for the home side .
Callum McGregor added a second after Griffiths opened the scoring at Firhill on Saturday and were comfortable despite a late penalty - after Steven Lawless had been fouled by Erik Sviatchenko - from Sean Welsh for the home side .