Thomas Baillie felt Kettering Town got “what they deserved” as the new year started with a 1-0 defeat at the hands of Rugby Town at Latimer Park.
Tommy Hull was sent off for two bookable offences in the second half having hit the crossbar just a few minutes earlier.
But the red card proved to be a decisive moment as Rugby eventually grabbed the winner through Sam Youngs late on.
It meant the Poppies’ lead at the top of the Evo-Stik Southern League Division One Central was cut to just four points as second-placed Aylesbury beat Aylesbury United in their derby clash.
But Kettering joint-boss Baillie was more concerned with his own team’s problems as they slipped to just a second home league defeat in this campaign in front of a season-high attendance of 872.
“We were not good enough, it’s as simple as that,” he said.
“Ultimately, we got what we deserved from the game.
“The sending-off changed the game because we knew that if we went in level at the break then the wind would be behind us in the second half.
“But it was a silly sending-off and Rugby eventually took advantage of that.
“They gave it everything and I am sure their manager will be hoping they show that same desire every week.
“I am as disappointed as I have been all season because we threw it away.
“You expect some players to step up in games like this and some didn’t on this occasion.”
The Poppies are set to return to action on Saturday when they host struggling Beaconsfield SYCOB.