Port Vale midfielder Chris Lines' superb free-kick was enough to earn victory over 10-man Tranmere Rovers.
The former Bristol Rovers man struck from 25 yards to net his first goal for Vale, who were playing under stand-in manager Rob Page for the first time.
Earlier, Tranmere's new loan signing Liam Ridehalgh had been sent off for a foul on Chris Birchall inside the box.
Rovers keeper Owain Fon Williams kept out top scorer Tom Pope's spot-kick but was powerless to stop Lines' winner.
It was a miserable debut for left-back Ridehalgh, who completed a three-month loan from Huddersfield prior to kick-off, while victory gave Page the perfect start to his tenure as Vale's temporary boss.
The former Wales international is in control of first-team affairs while
VIEW FROM THE DRESSING ROOM
Tranmere manager Ronnie Moore told BBC Radio Merseyside:
"It was cruel. Was it a sending-off? I don't know. Liam had started really brightly. If they score there, the referee doesn't send him off.
"For our general effort, commitment and play, I think we deserved to take something out of the game.
"I've said to the players that if they give that effort and desire they showed in the second half, then we will certainly be getting back to the right end of the table where we need to be."