DOHA (AFP)

Hong Kong's first Asian Cup match in over 55 years ended in a 3-1 defeat to the UAE on Sunday, the returning minnows on the wrong end of three big VAR calls in Qatar.

Two of the UAE's goals came from VAR-ruled penalties, while a late Hong Kong goal was chalked off after the referee checked the screen. Coach Jorn Andersen warned his players before the game that the "gap is very big" between themselves and the continent's footballing elite.

But there was no yawning gulf in class as the tournament's lowest-ranked side kicked off their campaign. In their first Asian Cup match since 1968, Hong Kong fell behind just after the half-hour mark.

Referee Muhammad Taqi was called to the pitch-side screen to rule on a possible handball in the box by Hong Kong defender Oliver Gerbig. After a lengthy check, a penalty was given and duly converted by Sultan Adil.

Hong Kong levelled four minutes after the break, Philip Chan bundling home an Everton Camargo cross. The UAE regained the lead almost instantly through Zayed Sultan as he slotted into an unguarded net.

With half an hour left, Andersen rolled the dice with an attacking double substitution, sending on forwards Stefan Pereira and Michael Udebuluzor. Hong Kong defender Li Ngai-hoi then survived another VAR scare, his tackle in the box ruled legal. As the clock ticked down Hong Kong pushed for a second equaliser, their chances helped by the addition of 10 minutes' stoppage time.

But after a third VAR check against them, the referee pointed once again to the spot and Yahya Al Ghassani converted. Hong Kong had the ball in the net one last time, but VAR intervened to deny them.

Meanwhile, two-goal Takumi Minamino admitted he was "surprised" by Vietnam after Asian Cup favourites Japan survived a scare in winning 4-2. The former Liverpool forward looked to have set Japan up for a comfortable afternoon when he scored early, only for Vietnam to come roaring back with two first-half goals.

Minamino scored again before Keito Nakamura restored Japan's lead on the stroke of half-time, before substitute Ayase Ueda made the game safe with a late fourth. Japan are hotly tipped to lift a record-extending fifth Asian Cup.

"I've been playing against Vietnam since I was young so I know how good a team they can be," said the 28-year-old, now at Monaco.

"But it wasn't just in defence – they were really good in attack as well. I was surprised by how good they were." Vietnam, who are coached by Japan's 2000 Asian Cup-winning boss Philippe Troussier, equalised five minutes after Minamino's opener when Nguyen Dinh Bac glanced a looping backwards header over the Japanese defence.

Pham Tuan Hai then stuffed home a loose ball at a free-kick to put the Southeast Asians in front on 33 minutes. Minamino led the fightback by rolling a precise first-time shot just inside the far post in the 45th minute.

Nakamura then put Japan back in front with a jaw-dropping strike from the edge of the box in first-half injury time.

"The first half was very difficult because we went behind, but I think we showed our strength as a team by coming back," said Minamino. "The first game of a tournament is always very important so I'm happy that we got three points."