Chonburi earned a share of the Thai League 1 top spot at least for a day when they edged PT Prachuap 1-0 at home last night.
Amadou Ouattara delivered the winner for Sharks 10 minutes into the second half and the visitors failed in their attempts to level the score.
The Sharks joined co-leaders Bangkok United and Ratchaburi, who are both scheduled to play their fifth games this evening, on 12 points.
Earlier on Friday night, former champions BG Pathum United laboured to their first league victory of the season.
After a goalless first half, Thailand midfielder Pathompon Charoenrattnapirom netted midway through the second half to give the Rabbits an unflattering 1-0 win over top-flight first-timers Lamphun Warriors.
Pathum coach Makoto Teguramori admitted after the home win that fitness of key players remained a major concern.
"The players were told before game that we have a busy schedule at the moment so they must help each other during the game," said Teguramori, "but they looked exhausted in the later stages of the first half.
"I told them to speed up their moves in the second half and we looked better.
"Although we scored only one goal, but I am happy with the number of chances we created.
"We have a match every three days and we are expected to claim three points from every game."
Pathompon found the net for the home team in the 72nd minute when he headed home a cross from defender Apisit Sorada.
Pathum will next host Port on Wednesday.