True Bangkok United's dream of taking over the second spot in Thai League 1 fell apart on Sunday night as they slumped to fourth place in the table instead.
Bangkok United were hoping to leapfrog Samut Prakan City into second place but were held to a surprise 2-2 draw by visiting Nakhon Ratchasima.
This allowed Chiang Rai United take over the second spot following their 2-1 victory over Chiangmai in a northern derby.
Defending champions Buriram United lead the standings with 38 points, two ahead of the Beetles.
Had it not been for quick late goals by Chananan Pombupha (81st minute) and Nelson Bonilla (84th), things would have been worse for Bangkok United.
Nakhon Ratchasima were cruising towards an upset following a brace by Bernard Henry early in the second half before the home team levelled the score.
Ekanit Panya and Bill Rosimar were the chief contributors for Chiang Rai United at their home ground. Evson Nascimento pulled one back for Chiangmai in the last minute.
The Beetles now hold a one-point edge on Samut Prakan, who were hammered 4-1 at home by Buriram on Saturday.
Meanwhile, Choketawee Promrut had a dream start as Port's new coach, guiding his side to a 1-0 home win over Sukhothai thanks to a second-half strike by Elias Dolah.
The victory ended a six-match dry spell for Port, who last week moved Jadet Meelarp to an inactive post and brought Choketawee in as their new coach.
Chainat moved out of the red zone after a 2-1 win at PTT Rayong.
In Saturday night's late game, SCG Muang Thong United edged 10-man Ratchaburi 2-1 to surge to seventh place in the league.
The Kirins' fifth win in six league matches was delivered by Heberty Fernandez and Myanmar striker Aung Thu, who scored in the either half. South Korean Yoo Jun-Soo netted for Ratchaburi in the dying moments.