Accrington Stanley were beaten 2-0 at Lincoln City after playing over 45 minutes with ten men as defender Farrend Rawson was sent off at Sincil Bank.
The red card incident occurred on the stroke of half-time and led to the penalty which Matt Green converted to put his side ahead following a tight half of football.
Rawson was adjudged by referee Seb Stockbridge to have pulled the striker back inside the area, however the on-loan centre-back didn't appear to make contact with any Imps man inside the area.
Stanley started the second-half strongly but they were struck by a hammer blow in the 57th minute as Matt Rhead scored to effectively put the game beyond John Coleman and his men.
There was a raucous atmosphere inside a packed Sincil Bank and the game burst into life immediately from the kick-off as Billy Kee tested Josh Vickers from distance inside the opening 30 seconds before Rhead stabbed over the bar from inside the six-yard box just seconds later.
Lincoln continued to look for the big forward and his strike partner Green with long balls into the penalty area, but the Stanley defence dealt well with the physical challenge.
The visitors tried to play their passing style but found opportunities hard to come by, while at the other end they had goalkeeper Aaron Chapman to thank for keeping them level, as he twice saved from Green who had powered his way into the area.
Superb work on the line from Mark Hughes prevented Stanley from falling behind as he cleared Harry Anderson's effort.
On the stroke of half-time another Imps long ball found its way behind the Reds back four, the ball found Chapman who had raced off his line but referee Stockbridge pointed to the spot and flashed an immediate red card at Rawson.
It sparked fury and bemusement on the touchline, and in the stands, but the decision for what could only have been a minor push or a pull-back stood, and Green sent Chapman the wrong way to make it 1-0 at the break.
The ten-men of Stanley made a strong start to the second period and were inches from an equaliser when Jordan Clark's header looped wide of the post.
But in the 57th minute Lincoln had a second, Neil Eardley found Rhead unmarked at the back post, the forward took a touch before calmly slotting the ball beyond Chapman.
Stanley continued to push their opponents hard, but they were frustrated into taking speculative shots from distance, Scott Brown and substitute Ben Richards-Everton tried their luck but couldn't threaten Vickers between the Lincoln posts as the home side held on to claim all three points.