After Ben Dawson made seven changes from the youngsters' Checkatrade Trophy defeat at Sunderland, the Irish centre-back was awarded a first start in United's second string, marking the occasion with a first-half strike for the Magpies.
After West Brom's early opener, the Magpies equalised following an Albion own goal. Minutes later, the visitors failed to clear their lines and, after a scramble inside the penalty area, the ball fell into the path of McEntee, who took no hesitation in burying his effort into the net.
Second-half goals from Rosaire Longelo and Yannick Touré secured Newcastle three points, resulting in a memorable under-23s bow for McEntee, who has featured regularly for Dave Watson's under-18s this term.
"It's great to get the three points and score four goals," the 18-year-old told nufc.co.uk. "It was incredible to make my debut and I was very happy to get on the scoresheet.
"The ball was bobbling around the box and I just pulled on it. When I saw the ball hit the roof of the net, I was absolutely buzzing. It was great on a personal level, but it was also an important goal for the team in order to get the victory.
"West Brom dominated the opening minutes and after conceding, we managed to grab one back and kick on by taking the lead, which helped us in winning the game.
"Overall, it was a tough game. Playing in defence, the opposition had a lot of good attacking players but I feel like we were able to defend well at times and limit their chances."
A representative of Republic of Ireland at under-17 level, McEntee accepted there were differences in making the step up from youth level but is determined to make his mark on United's second string squad.
"I feel like I needed to move the ball a lot quicker and it was much more physical then playing with the under-18s. I just need to be that extra one step ahead when playing with the under-23s so I can mix well with them, even in training with my team-mates.
"Now, I just want to get back on the pitch and play again. Making my debut was fantastic and hopefully there are many more games to come."
