Less than a week after taking over the top spot in Thai League 1, leaders Port were given a rude wake-up call as they suffered a shock 2-1 defeat at the hands of Sukhothai on Friday night.
Hosts Sukhothai, languishing in the three-team red zone before the kick-off at Thalay Luang Stadium, were off to a good start when John Baggio set up Nelson Bonilla to score against his former club in the fourth minute.
Port equalised in the last minute of the first half when Teerasak Poeiphimai beat an offside trap and combined with Bordin Phala to pave the way for Barros Tardeli to grab the leveller.
Sukhothai stunned the league leaders with another strike after 70 minutes when substitute Kritsana Kasemkulvilai found the net.
Port went all out on attack and Tardeli missed the target with a header from close range.
Also on Friday night, hosts Police Tero lost 3-1 to Khon Kaen United.