Robert Lewandowski scored a hat-trick as Barcelona opened their Champions League campaign with a comfortable 5-1 win over Viktoria Plzen at the Nou Camp.Franck Kessie headed the LaLiga side in front after 13 minutes, before Plzen thought they had been awarded a penalty for a foul by Andreas Christensen on winger John Mosquera but the decision was overturned following a VAR review.Lewandowski slotted in a second on 34 minutes, his sixth Barcelona goal since a summer move from Bayern Munich.Jan Sykora had the travelling Czech support celebrating when he headed past Marc-Andre ter Stegen, with VAR ruling the goal onside.Lewandowski, though, further extended Barca's lead when he nodded in a cross from Ousmane Dembele during first-half stoppage time.The Poland striker completed his treble in the 67th minute when he fired home a volley from the edge of the Plzen penalty area, taking his personal tally to 89 Champions League goals, with substitute Ferran Torres adding a fifth.In the other Group C game, Bayern Munich won 2-0 at Inter Milan with an early strike from Leroy Sane and a second-half own goal from defender Danilo D’Ambrosio.Rangers’ first game back in the Champions League group stage after a 12-year absence ended with a 4-0 defeat at Ajax – where the Scottish side were 3-0 down inside 33 minutes.Edson Alvarez, Steven Berghuis and Mohammed Kudus put the Dutchmen in total control, before Rangers defender Borna Barisic saw a second-half goal ruled out by VAR and Steven Bergwijn added a fourth with 10 minutes left.Sporting Lisbon won 3-0 at Eintracht Frankfurt with second-half goals from Marcus Edwards, Trincao and Nuno Santos.In Group B, there was late drama at the Metropolitano Stadium as Antoine Griezmann came off the