January arrival Pritchard struck on seven minutes to bag his first goal for the club before Junior Stanislas' delicate finish to level things up just six minutes later.
Club record signing Steve Mounié played a big part, netting Huddersfield's second before the break and forcing Steve Cook into an own goal later on to make it 3-1.
Pritchard won a penalty deep into stoppage time and gave the subsequent spot-kick to Rajiv van La Parra, who stepped up and smashed home to emphatically claim The Terriers' first points of 2018.
Full home debut marked with a first goal
The raucous support Huddersfield Town receive at home games has already earned plenty of plaudits in their inaugural season as a top-flight club, and Pritchard didn't forget to acknowledge it after full-time.
"I tried talking to the boys but they couldn't hear me, the atmosphere is great from the first whistle to the last. The connection between the players and the fans is brilliant."
He marked his full home debut as a Huddersfield player with a tremendous goal to open the scoring after less than 10 minutes and admitted that it's relieved him of pressure.
"It was [a great feeling]. It was a big weight off my shoulders to get the goal and obviously when we conceded we didn't just stop, we kept on going and deserved the points."
Fully deserved win in crucial match
AFC Bournemouth are part of the large group of teams all in danger of relegation from the Premier League this season and Pritchard stressed the importance of three points after results in Saturday's fixtures.
"Massive [win], needed. With the run we've had, we knew today was a massive game with results going the other way yesterday. I thought we came out of the blocks brilliantly and it was a well-deserved 4-1 win."
Despite being in full control in the opening stages of the clash, Huddersfield were dealt a blow as Bournemouth equalised almost straight after the opener.
Pritchard made sure to praise the goal, and how his team recovered, saying: "Give them a yard and they'll take it like they did with their goal. It was a great finish but we kept going and have goals to show that."
Terriers remembered to be fearless
The manner of which the further three goals were scored after the visitors drew level was a clear reminder of the 'Terriers spirit' and identity of David Wagner's side.
Town are built on a high-pressure, organised system under the German head coach and it proved to work perfectly against the Cherries, and Pritchard admired the focus of his teammates.
"We tried to work off the ball, win it and cause them problems because if you give them space they've got good players who keep the ball very well. They showed that in spells but we were dogged and deserved it."
The 24-year-old also made sure to mention the Terriers' evident confidence, stating: "We need to keep that confidence up. We've been saying for the past few days to just be fearless, and we were today."