South Korea passed a physical test from Bahrain to win their Asian Cup Group E opener 3-1 thanks to Lee Kang-in's second-half double at the Jassim Bin Hamad Stadium on Monday.

With the score at 1-1 after goals from Hwang In-Beom and Bahrain's Abdullah Al-Hashsash, Paris St Germain's Lee turned on the style with two lethal strikes that had the South Korea fans at the small 15,000 capacity arena screaming in delight.

A stop-start encounter had plenty of fouls in the first half and although there was no malice in the challenges, South Korea had three players on yellow cards in the first half hour - including centre back Kim Min-Jae.

"We knew it wasn't going to be easy playing Bahrain, it turned out to be scrappy with a number of yellow cards today," South Korea coach Juergen Klinsmann told reporters.

"It was a tricky game and had a lot to do with the Chinese referee (Ning Ma) giving too many yellow cards early. That's why I took off Min-Jae, because if they made a slight foul he'd get sent off."

The Korean fans had seen enough to start booing the referee whenever he kept his cards in his pocket for a foul from Bahrain and the pressure paid off when Ali Madan went into the book for a tough challenge.

South Korea then took the lead through a quick flowing move down the left wing where the ball was crossed into the box and Hwang curled home through a crowd of Bahrain defenders, two of whom ran into each other while tracking back.

But Bahrain came out fighting in the second half and they were duly rewarded six minutes in when Al-Hashsash found space in the box and slotted home into the bottom corner.

LEAD RESTORED

However, South Korea were not deterred and the east Asian side restored their lead five minutes later through Lee, who pulled the trigger from outside the box and saw his superb effort curl into the net.

The PSG playmaker doubled his tally soon after when he received the ball from Hwang, escaped his marker with some quick feet and showed some panache as he curled another shot past goalkeeper Ibrahim Lutfalla inside the far post.

Lee, whose second goal took him joint-top of the tournament's scoring charts, said Korea's eyes are on the prize but they are taking things one game at a time.

"Everyone in the locker room and people back home are waiting for this trophy we haven't won in 64 years," he said.

"We're motivated but it's still too early to talk about winning the championship."

Son Heung-min had a late opportunity to score when he was released in the box but his shot went wide while the Tottenham Hotspur forward was also booked for simulation later when he attempted to win a penalty.

The Korea skipper had also been fouled heavily twice in the game and took his time to get back to his feet, with the 31-year-old admitting that Bahrain were not easy opponents.

"It was a tough game, as we expected. Bahrain obviously prepared really well and it was tough to break (them down), especially when we went up 1-0," Son said.

"Obviously we have to do better. But I think the most important thing is that we won the game."