An 'angry' Jan Siewert has admonished Aaron Mooy's Huddersfield Town for a late loss of concentration that cost them a point in the 1-0 loss at Mat Ryan's Brighton & Hove Albion.
Florin Andone ghosted unmarked onto an Anthony Knockaert cross in the 79th minute and nodded home the winner for the second successive meeting between these teams.
Huddersfield arrived at Amex Stadium buoyed by a long-awaited victory over Wolverhampton Wanderers in midweek but the optimism Siewert spoke of after that match made way for a decidedly different mood at Brighton.
The German condemned his players for failing to adequately react as a quickly-taken set-piece afforded Knockaert time to measure his cross for substitute Andone.
"We lost the game because of a free-kick and this makes me totally angry," Siewert told the BBC.
"We were not switched on. From the first minute to the 95th or 96th you have to be switched on. I am angry, we were running and fighting.
"I'm angry about it because in the Premier League you can't allow such situations. We gave everything here and we deserved a point. We tried to play forward.
"I know it's not easy against Brighton, they have good intensity and this early substitution [of Jonathan Hogg] definitely affected the game.
"We had many shots on target, we had possibilities but we lost because of a free-kick."
The defeat came after a largely subdued opening hour and left bottom-placed Huddersfield 13 points adrift of safety, a seemingly impossible gap to bridge with nine games to play.
Brighton are in a far brighter position having climbed five points clear of the drop zone with a much-needed first win of 2019.
Seagulls boss Chris Hughton said he was relieved by the end of a poor run of results but disagreed with Siewert's assessment that a draw would have been a fairer reflection of the contest.
"It was not so dramatically different to other games where we have had good spells and difficult spells," Hughton said.
"It's almost a perfect result. We kept a clean sheet, which makes us a little bit more solid. I don't think anyone would feel we didn't deserve to win in the end."