Real Madrid got their Champions League title defence off to a strong start on Wednesday by convincingly beating AS Roma 3-0 at home with goals from Isco, Gareth Bale and a stoppage-time strike from returning striker Mariano Diaz.

Julen Lopetegui's side, who have won the last three editions of the competition, made a flying start against last season's semi-finalists Roma, but took their time to make their dominance count.

Isco, Bale, Sergio Ramos and Dani Carvajal all missed relatively simple chances for the hosts, who were not far from going behind when Turkish youngster Cengiz Under darted in behind the defence but sent his finish flying wide.

It took a wonderfully struck free kick from Isco right at the end of the first half for Real to take a deserved lead, and their dominance continued in the second half.

Bale saw a deflected shot bounce off the crossbar shortly after the interval but got the goal he craved not long after, racing on to a raking pass from former Tottenham Hotspur team mate Luka Modric and arrowing in off the post in the 58th minute.

Roma did not completely wilt after conceding again and it took an impressive save from Keylor Navas to deny the lively Under, as the Costa Rican goalkeeper justified his inclusion in the team after briefly losing his place to Thibaut Courtois.

Roma goalkeeper Robin Olsen did his best to keep the scoreline dignified by denying Isco and Marco Asensio but was powerless to stop Mariano.

The striker was playing his first game after returning to Madrid from Olympique Lyonnais and got the crowd on their feet with a wonderful curling strike into the top corner.

Real lead Champions League Group G with three points after Viktoria Plzen blew a two-goal lead to draw 2-2 at home to CSKA Moscow, who equalised in the 95th minute with a converted penalty from Croatian striker Nikola Vlasic.