Thai League 1 celler-dwellers Chiangmai on Saturday pulled off a big upset as they rallied past seventh-ranked Chonburi for a 2-1 home victory which failed to lift them off the bottom.
The Sharks took the lead through Krissada Kaman, who found the net in the ninth minute.
Facing a barrage of relentless attacks, Chonburi finally wilted under pressure and let Evson Nascimento pick up the equaliser for the home team in 22nd minute.
Chiangmai had a lucky break in injury time when an Eliandro Santos shot was deflected by Chonburi's Junior Lopes into his own goal.
Hosts Ratchaburi Mitr Phol salvaged a point with a second-half Javier Patino goal earning them a 1-1 draw against PTT Rayong.
With new Thailand coach Akira Nishino in the stands, Rayong skipper Victor Cardozo scored off a penalty in the 39th but only to see Jakkraphan Pornsai set up Patino for the equaliser three minutes after the break.
Also on Saturday night, Joel Sami extended PT Prachuap's winless streak to eight games with a 70th-minute leveller for hosts Sukhothai in a 1-1 draw.
Prachuap, who went ahead in the 55th minute when Maurinho Junior scored, remain dangerously close to the drop zone.
Meanwhile, fierce rivals Port and SCG Muang Thong United square off at PAT Stadium on Sunday.
Both have enjoyed good runs under new coaches -- Choketawee Promrut at Port and Alexandre Gama at Muang Thong.
Leaders Buriram United are at Trat who lost to the same opponents at the same venue in the FA Cup quarter-finals on Wednesday.
Second-placed Chiang Rai United, who had a brief spell at the top of the table last week, will be hoping to extend Samut Prakan's miserable run.