​MESSI ON FIRE AS BARCA THRASES MAN CITY* OZIL BAGS HAT-TRICK FOR GUNNERS

Lionel Messi marked his return to the Barcelona starting line-up with a hat-trick as a 4-0 win over 10-man Manchester City preserved a perfect start to this season's Champions League campaign for Luis Enrique's men.

Messi came off the bench following a groin injury to score in the 4-0 weekend win over Deportivo La Coruna and he netted a 17th-minute opener at Camp Nou on Wednesday.

City boss Pep Guardiola was back at the ground with which he will for ever be inextricably linked and his team posed plenty of questions either side of Barcelona going in front, until a mindless red card for Claudio Bravo resulted in the game racing away from them.

It was the fourth time in five Champions League defeats to Barcelona that City found themselves operating with reduced numbers and a little over a quarter of an hour later, Messi made the matchball his own.

Meanwhile, Mesut Ozil was devastating in front of goal with a second-half hat-trick as Arsenal surged to an easy 6-0 win over Ludogorets in the Champions League on Wednesday.

Alexis Sanchez had opened the floodgates in the 12th minute before Walcott doubled their lead before half time.

The avalanche of goals continued after the break as Alex Oxlade-Chamberlain immediately got in on the scoring, before Ozil capped off a fine win with three cool finishes.