Ronny Deila's tenure as Celtic boss began with a narrow but deserved 1-0 win in the first leg of their Champions League second round qualifier against KR Reykjavik, thanks to a late goal from debutant Callum McGregor.
Former Newcastle goalkeeper Forster pulled off the save of the gamen the 23rd minute when Martin sent in a shot from 25 yards.
He went to Brazil with the England squad but was the only one of 23 squad members not given a game.
The Celtic match took place in the somewhat surreal surroundings of the KR-vollur stadium in Iceland, which housed only around 1,500 fans in its one stand, approximately 200 of whom were away supporters.
With Celtic Park out of commission due to the 2014 Commonwealth Games, the return fixture will be at Murrayfield in Edinburgh next Tuesday night.