Liverpool stuns Arsenal, Ibrahimovic stars for Man United

Liverpool's manager Jurgen Klopp shouts orders during the English Premier League soccer match between Arsenal and Liverpool at the Emirates Stadium in London, Sunday Aug. 14, 2016. (AP Photo/Tim Ireland) (The Associated Press)

Liverpool's Sadio Mane, right, breaks away from Arsenal's Calum Chambers during the English Premier League soccer match between Arsenal and Liverpool at the Emirates Stadium in London, Sunday Aug. 14, 2016. (AP Photo/Tim Ireland) (The Associated Press)

Manchester United's Tema Manager Jose Mourinho applauds t Manchester United's Wayne Rooney after scoring during the English Premier League soccer match between Bournemouth and Manchester United at Vitality Stadium in Bournemouth, England, Sunday, Aug. 14, 2016. (AP Photo/Frank Augstein) (The Associated Press)

A rampant Liverpool came from behind to beat Arsenal 4-3, while Manchester United began its new era under Jose Mourinho with a 3-1 win at Bournemouth in their opening games of the English Premier League season on Sunday.

Theo Walcott put Arsenal ahead at Emirates Stadium, but his side was soon overwhelmed after Liverpool leveled through Philippe Coutinho on the stroke of halftime and then raced into a 4-1 lead after the break.

Arsenal's defense was shredded by Liverpool's fluent passing and clinical finishing. Classy goals by Adam Lallana, Coutinho and Sadio Mane put the Reds in control before Alex Oxlade-Chamberlain and Calum Chambers scored to give Arsenal hope.

Mourinho's first league game in charge of United included a fine goal by 34-year-old Zlatan Ibrahimovic on his EPL debut.