After the match, Ngongotaha coach Shane Davis was clearly frustrated with his team's second-half performance, which saw them almost give up a big lead.
"We played crap. We had a pretty consistent first half but then we just stayed in the changing rooms in the second half," he said. "It was good [that we won] but a draw would have been a fair result."
United assistant coach Tim Barnard said their poor start to the game cost his team.
"We just gifted them three early goals. But we are new to this league and once we got that tempo going we were brilliant."
United were promoted back into the WaiBOP Premiership this year after finishing second in the WaiBOP Championship last season.
The star player for Ngongotaha was striker Mitch Miller who scored a hat-trick inside the opening 25 minutes.
Miller tapped in from close range, off the back of a Dave Haua header, to open the scoring then added a penalty and a header from a set piece to complete his hat-trick.
Ngongotaha's Luke Barker showed some good composure and added his name to the score sheet as the side took a 4-0 lead into the break.
United had not mustered a single shot in the first half but were excellent in the second period.
Hill scored the first two goals for the visitors, the first a nice display of individual skill and the second coming off the back of a long Lawrie Scott pass. The 50m ball was met first time by an advancing Hill who hooked the ball across the goal and into the bottom corner.
Steffano Riley and Scott had a great game in midfield as the visitors started to claw back the lead.
Defender Dave Cheater added the third goal for United with a header from a corner, but the score would remain 4-3 at full-time.
-WaiBOP Football round two results on Saturday:
Premiership: Papamoa 1-2 Melville United, Tauranga City 2-4 Cambridge, Matamata Swifts 3-1 Otumoetai, Ngongotaha 4-3 Rotorua United, Waikato Unicol 4-3 Tauranga Boys' College, Tauranga Old Blues 2-4 Katikati.
Championship: Matamata Swifts 2-2 Te Puke, Ngongotaha 1-4 Claudelands, Tauranga Old Blues 2-2 Cambridge, Te Awamutu 1-1 Whakatane Town, West Hamilton 3-2 Tokoroa, Kawerau bye.