By Gabriel TanFollow @@gabetan13
Despite being favourites for the clash at the Chonburi Stadium, the Sharks struggled to break down a stubborn opposition defence, although their prospects were given a boost 14 minutes from time when Army midfielder Jung Myung-oh was sent off for a second bookable offence.
And just as the game entered injury-time, Chonburi stole all three points when Ivan Boskovic netted what proved to be the winner.
BEC Tero Sasana also picked up their first win of the season after beating newly-promoted Ratchaburi 1-0 at the Ratchaburi Stadium, courtesy of a 36th-minute strike from Brazilian striker Cleiton Silva.
Pattaya United failed to build on last week's impressive 2-0 win over Samut Songkhram as they relinquished a lead to fall to a 2-1 defeat at home to Osotspa Saraburi.
Having edged ahead on the stroke of halftime through an Anuwat Inyin effort, the Dolphins were pegged back six minutes after the restart when Suradej Thongchai equalised, before Thailand international Apipoo Suntornpanavej struck in the 57th minute to hand Osotspa all three points.
TOT and Police United remain unbeaten after both sides played out a 1-1 draw at the TOT Stadium Chaeng Watthana.
Following a goalless first half, Lee Han-gook fired Police in front with a rasping drive past Mantehwa Lahmsombat, but TOT forced the draw 12 minutes from time when Panomkorn Saisorn drilled home the equaliser.
Finally, Thailand international Sompong Soleb scored in the 67th minute to earn Bangkok United a 1-1 draw at home to Samut Songkhram, who had taken the lead two minutes earlier through a Park Jae-hyun penalty.
Sunday's Thai Premier League Results
Bangkok United 1-1 Samut Songkhram
Pattaya United 1-2 Osotspa Saraburi
Ratchaburi 0-1 BEC Tero Sasana
TOT 1-1 Police United
Chonburi 1-0 Army United
Image courtesy of Chonburi FC