Lionel Messi scored twice as 10-man Barcelona eased to an opening day win over Elche in Luis Enrique’s first La Liga match in charge.
Debutant Munir and Andres Iniesta hit the bar for the hosts before Messi drilled in low from an angle.
Seconds later Javier Mascherano was sent off for a professional foul on Garry Rodrigues, but Munir doubled the lead with a chip soon after the break.
Messi slotted in his second after beating three defenders.
The Argentine was on the losing side in the World Cup final against Germany in July but, despite only playing one pre-season friendly, looked refreshed and ready to play a key role in a new-look Barca’s title assault.
Former Barcelona midfielder Enrique replaced Tata Martino as manager in the summer, after the Argentine presided over the club’s first season without a major trophy since 2007-08.
Enrique has been busy in the transfer market, including signing Luis Suarez from Liverpool, although the Uruguayan is not available after being banned for four months for biting Italy’s Giorgio Chiellini at the World Cup.
The new manager has also brought in Ivan Rakitic from Sevilla for £18m and Thomas Vermaelen from Arsenal for £15m in an attempt to freshen up the squad while Barca’s Fifa-imposed transfer ban was still suspended.
Enrique handed debuts to Rakitic, goalkeeper Claudio Bravo, centre-back Jeremy Mathieu and young attackers Munir and Rafinha.
Forward Munir, 18, a graduate from Barcelona B, almost made an explosive introduction as he fired a fierce shot against the upright after a neat turn on 20 minutes, before Andres Iniesta’s 20-yard strike followed suit.
For all their problems, Barcelona would have defended their league title last season with a win over Atletico Madrid in the last match of the campaign.
And it was their established star, Messi, who broke the deadlock three minutes before the break, driving into the Elche box before shooting low into the far corner.
What looked like being a routine victory though was complicated a minute later as Mascherano was caught out by a long ball and, after cynically hauling down Garry Rodrigues, shown a straight red card.
The impressive Munir ensured the numerical disadvantage was not to prove too problematic, flicking Rakitic’s pass over goalkeper Tyton a minute into the second half.
Elche only escaped relegation by a point last season and were left helpless as Messi waltzed past three defenders before sliding the ball into the corner of the net from the edge of the area.