A 76th minute header from substitute Ekkachai Sumrei ensured Buriram pulled of an impressive 2-1 home win over Uzbek powerhouse Bunyodkor.
Bunyodkor's second choice stopper, Murod Zukharov, was the busier keeper early doors. First, he scooped away Theerathon's free kick with his feet after it had came through a cluster of players, and soon afterwards he had to parry away an Adisak shot.
Buriram's early pressure paid off when they took the lead in the 17th minute. A delightful ball from Jirawat skiffed off the back of Anawin past Zukharov after the Buriram winger had snuck in behind the Bunyodkor defence.
Six minutes later, Buriram should have doubled their advantage, but Kai Hirano blazed a rebound over the bar after the Uzbek keeper had been forced into a save.
Bunyodkor had done virtually nothing in the opening 30 minutes, but they gradually improved as the half neared the 45 minutes mark. The Buriram defence were living dangerously as the Uzbek side delivered some testing balls from set pieces.
The persistence of the the Swallows finally paid off as they levelled in first half injury time. It was no surprise that their goal came following a set piece. Sivakorn blocked a delivery from the right with his legs, but it was then chipped across the goal for substitute Igor Taran to volley home.
That goal seemed to take the wind out of Buriram's sails as they found it difficult to keep the same attacking tempo in the early stages of the second half.
On the hour, Bunyodkor almost made it 2-1 when Murzoev's shot on the turn rattled the top of the goal stanchion.
However, on 76 minutes Buriram retook the lead when Ekkachai looped a header inside the far post following a free kick from his former Thai Port colleague Jirawat.
The expected fightback from Bunyodkor never really materialized although they should have had a penalty in the 92nd minute when Anawin bundled over Taran as he was about to pull the trigger. The Aussie whistler, who'd otherwise had a good game, failed to award the spot kick and some would say it was a bit of pay back after the number 9 had tumbled rather easily on a couple of occasions prior to this.
Nonetheless, Buriram claimed a deserved 2-1 victory, but Bunyodkor will still be favorites to progress when the second leg is played next Tuesday at the recently built Bunyodkor Stadium.
Man of the Match: Theerathon - Great attacking play and delivery from set pieces mixed in with some petulance