Dudu's hat-trick inspired Osotspa as they came from behind to earn a 3-1 win that ended Army's unbeaten start to the season.
Army had the better of the early exchanges and Sarayoot opened the scoring on 11 minutes as he bulleted home a header from a pinpoint Narong cross.
Osotspa were back in the game midway through the half when Dudu levelled from the spot. The penalty wasn't initially awarded after appeals for handball in the box. The tantrum thrown by Dudu seemed to sway the match officials as the referee eventually pointed to the penalty spot after consultation with his assistant. It was then the turn of Army players to vent their frustrations and the kick was eventually converted four minutes after the original incident had occurred.
The away side started playing with more confidence and freedom, and Army's keeper, Kosin, made a great double save to keep the score level.
As the interval approached, Army's rearguard were cut apart from a pass from Suradej, and Dudu slotted the ball under the keeper to give Osotspa a 2-1 lead. The half time whistle was greeted with jeers from the home fans towards the match officials as they left the field.
Army needed to up the stakes and as they pushed forward it gave the Saraburi side the chance to counter attack. Osotspa should have wrapped the game up twice late on when Zuke and Sarawut fluffed their lines after being clean through on goal.
But Osotspa weren't to be denied a third and Dudu completed his first hat-trick for the club when he easily shrugged off Suwittaya to hit the roof of the net with a rasping drive.
Most Army fans would have conceded that it was a fair win for the away side. Army started brightly but the stuffing seemed to be knocked out of them after the penalty and they never really recovered. Dudu was by far the best player on the park but his petulant whining and hissy fits make him the pantomime villain. It was noticeable that when he scored his first two goals, none of his team mates joined him as he celebrated alone in front of the away section.
As for the referee and linesmen, they need to be more assertive when making decisions. For the penalty award they were bullied by the players of both sides as uncertainty reigned. The referee having lost face then decided to yellow card every tackle after that to show he was the man in charge.