|Lionel Messi celebrates during Barca's 3-1 win over Greek side Olympiacos|
Gerard Pique was sent off two minutes before halftime for two bookings, one for tugging an opponent’s shirt and the other for slapping the ball into the net, but Barca were barely threatened after the break by a hopeless Olympiakos side who are badly underperforming in their defence of the Greek top flight.
Barca took the lead in the 18th minute on a rain swept evening at a sparsely attended Nou Camp when visiting defender Dimitrios Nikolaou turned Gerard Deulofeu’s cross into his own net.
Messi struck his landmark goal in Europe from a free kick in the 61st minute to double Barca’s lead. It was his 97th goal in the Champions League, while his other three strikes in Europe came in the UEFA Super Cup.
The Argentine then carved his way through the hapless visiting defence moments later to tee up France left back Lucas Digne to score his first goal in the Champions League for Barca.
Greek defender Nikolaou put the ball in the net for the second time in the game by heading home from a corner at the other end to give Olympiakos a scantly deserved consolation goal in the 89th minute.