Chonburi FC came from behind to beat nine-man Muang Thong United 2-1 for only their third win of the Thai Premier League season last night.
A first-half stunner from Nurul Sriyankem proved decisive as the Sharks picked up all three points at their Chonburi Stadium.
Mario Gjurovski gave Muang Thong the lead after just 15 minutes but Thiago Cunha put Chonburi back on level terms with a penalty a few minutes later.
Muang Thong's defeat gave Buriram some breathing space at the top of the table as the Thunder Castle remained four points clear of both the Kirins and Bangkok Glass, who lost 1-0 away to Osotspa in Saturday's late kick-off game.
Gjurovski gave Muang Thong the lead when the Macedonian playmaker fired home following a cross from Chananan Pombubpha.
A few minutes later Chonburi were awarded a penalty after Cunha was fouled by Muang Thong defender Sarawut Kallayanabundit.
The foul appeared to be on the edge of the box but after a long protest, Cunha stepped up and sent Muang Thong goalkeeper Wisanusak Kaewruang the wrong way to make it 1-1.
Sarawut was sent off after receiving his second yellow card for a foul on Leandro Assumpcao, who was clean through on the left side, in the 37th minute.
SEA Games star Nurul then put Chonburi ahead in the 40th with a delightful curling shot over Wisanusak from outside the box.
Things got worse for Muang Thong in first-half stoppage-time when striker Cleiton Silva was sent off after he kicked Kroekrit Taweekarn.
The sides continued to battle after the break, but the Sharks failed to extend their lead, while nine-man Muang Thong were unable to find an equaliser.
Muang Thong remained second on 24 points, four behind Buriram. Bangkok Glass were third, also on 24 points.
Chonburi moved up to eighth in the standings with 17 points.
In the early games, a penalty from Noah Chivuta handed Nakhon Ratchasima all three points at home against BEC Tero Sasana while TOT SC rallied for a 2-2 home draw with Suphanburi.