The Bluebirds have improved dramatically since the former Forest Green Rovers and Gillingham boss took over towards the end of October.
Substitute Jordan White’s header was enough to secure another three points as Barrow made it four wins in six games under Pennock.
The Cumbrians recovered from a poor opening 45 minutes to record their third away victory on the bounce.
“I wasn’t overly pleased with the first half performance because Halifax were very dominant and they looked strong,” Pennock told Barrow’s Youtube channel.
“We got into half time and sorted this, that and the other out and I think we deserved the win in the end.
“I take my hat off to the players. This is a tough place to come, they had to roll their sleeves up and to win 1-0 is very pleasing.”
Striker White popped up with the winning goal just seconds after replacing Adi Yussuf in the 69th minute - a substitution that proved to be pivotal.
“Sometimes they come off and this one did,” Pennock added. “I said to Jordan ‘go and get the winner’ and it’s unbelievable how these things happen.
“Jordan has had to be patient with Byron (Harrison) and Adi playing well so I’m really pleased for him.”
The victory moved Barrow up to 18th and, vitally, seven points clear of the relegation zone.
Pennock said: “It’s absolutely massive. I said after we lost 3-0 to Bromley last week that there will be bumps and bruises along the way.
“We’re all in this together. There’s a good feeling around the club at the moment and we’ve got to keep climbing up the league because you can easily get sucked back in.”