Jeonbuk Motors came from behind to seize the initiative in the AFC Champions League final with a 2-1 win over Al Ain.
Danilo Asprilla's away goal will give the Emirati side a chance when they host next week's second leg, but momentum is with Jeonbuk thanks to Leonardo's double.
Al Ain, led by captain Omar Abdulrahman, showed plenty of promise on the counter-attack, but sloppy defence let them down and the South Koreans perhaps ought to have scored more.
They certainly should have had a penalty in a scrappy first half when Mohammed Fayez kicked Kim Bo-kyung a few yards inside in the box, but the referee gave a free-kick on the edge of the area.
Al Ain aimed a number of long-range efforts off target as the first half ended goalless, but the game burst into life after the break.
Abdulrahman brought a superb reaction stop out of Kwoun Sun-tae before Kim Shin-wook scuffed over at the other end moments later.
Asprilla and Leonardo both wasted one-on-one chances with heavy touches within a minute of each other, but the Colombian was more sure-footed in the 63rd minute.
Abdulrahman had set up his earlier chance and again pulled the strings from the right wing, holding off two challenges before chipping into Asprilla, who slammed a left-footed half-volley into the top corner from 20 yards.
Kwoun almost gifted Al Ain a second when he ran out of his box, but Caio could not capitalise and Jeonbuk were quickly back on level terms as Kim played the ball to Leonardo on the left flank and he dipped inside before rocketing into the net from long distance.
Jeonbuk piled on the pressure and Fayez was penalised for a foul inside the area when he hauled down Kim five yards out - Leonardo calmly stroking home the penalty to complete the turnaround.
Lee Dong-gook had a header cleared off the line as the hosts tried to stretch their advantage and they will have to hold firm next week against an Al Ain side who have not lost in five home games in the Champions League.