Defending champions and hosts Qatar got their Asian Cup campaign off to a flying start with a 3-0 win over Lebanon in the tournament's opening game on Friday.

Akram Afif rifled in a shot on the stroke of half-time to put the 2022 World Cup hosts ahead, before Almoez Ali doubled their lead after the break and Afif bagged a late third.

Over 80,000 fans initially packed into the Lusail Stadium, where a Lionel Messi-inspired Argentina beat France on penalties in the World Cup final 13 months ago.

Qatar's win over Lebanon did not have the same drama and some spectators left as early as half-time, even with the home team winning.

By the final whistle there were swathes of empty seats.

But it was a welcome start for a team that claimed their first Asian Cup five years ago and only changed their coach last month, with Tintin Marquez replacing Carlos Queiroz.

Qatar stunned Japan in the 2019 final in the United Arab Emirates, lifting the trophy after winning every game they played at the tournament.

But they flopped on home soil at the World Cup, making a first-round exit after losing all three games.

Qatar were far more assured against a Lebanon side playing in only their third Asian Cup.

Ali, who scored an Asian Cup-record nine goals and was named player of the tournament in 2019, had the ball in the net as early as the sixth minute.

The striker latched onto a pass and slipped the ball past Lebanon goalkeeper Mostafa Matar, only for a VAR check to rule him offside.

Afif, another star of Qatar's 2019 win, went close when he hit the crossbar with a header on the half-hour mark.

But the forward would not be denied as the game crept closer to half-time, slotting the ball home with a right-foot shot after Ali had laid it off to him in the box.

Qatar hit their stride after the break and were rewarded with their second goal of the game in the 56th minute.

A neat passing move saw the ball worked out to Mohammed Waad on the left, and the defender picked out Ali to head past Matar.

The huge crowd began to filter out after Qatar's second goal.

They missed a deft finish from Afif for Qatar's third goal in the 96th minute, putting the final touch on an impressive individual performance.

Qatar also beat Lebanon in their opening game of the 2019 Asian Cup.

They will face Tajikistan in their next game on Wednesday, with China the other team in Group A.

Saturday's action begins with Australia taking on India, before China play Tajikistan and Uzbekistan face Syria.