Barcelona opened up its Champions League campaign against last season's finalists, Juventus, with a 3-nil victory
The Argentine superstar opened the scoring with a pinpoint effort across Gianluigi Buffon on the stroke of half-time.
Croatia midfielder Ivan Rakitich finished from close range after Messi's low cross was diverted away from goal in the 56th minute.
Messi got his double in the 66th minute when he left Buffon with no chance against another left-footed strike, which smacked the lower corner of his net.