Celtic defeated Icelandic side Stjarnan 2-0 at Parkhead in the first leg of their Champions League second-round qualifier on Wednesday night.
Former Manchester City defender Dedryck Boyata scored a debut goal just before half-time and Stefan Johansen struck early in the second period.
Substitute Leigh Griffiths had the chance to add a third goal but his penalty was saved by former Motherwell keeper Gunnar Nielsen.
