The young Magpies headed into the half-time break on goalless terms at Whitley Park before Westendorf, making his first full start for United's second-string since signing his first professional contract last week, broke the deadlock with a composed second-half finish.
Cameron Ferguson's close-range finish, the striker's third goal in his last five competitive fixtures at under-23 level, doubled the hosts' advantage as Elliott Dickman's side leapfrogged their Villans counterparts into fourth place of Division Two, maintaining their hunt for the play-off spots.
"Everyone is feeling happy," the 20-year-old striker, who scored two goals in four trial games for Newcastle's under-23 side in October, told nufc.co.uk. "We lost last week against Nottingham Forest so we wanted to get back on track and we did exactly that. I'm delighted to score my first goal for Newcastle but the most important thing was that the team got three points.
"The first 20 minutes or so was tough. We were a bit rusty and started the game slow but we got back into it towards the final 15 minutes of the first-half. At half-time, the coaches told us to stay more compact and we came out strongly so I'm delighted.
"Harps (Steve Harper) was on me, asking when I was going to score my official goal! Obviously, I scored two when I was on trial but it feels even sweeter to score my first official goal for Newcastle. I've been working very hard and this is a reward for all of that.
"It was very important to score the second goal as it killed off the game - I was delighted for Cam to score too. We also kept a clean sheet, which was great as we've been working hard all this week on our defending and counter-attacking. All we worked on in the build-up happened."
Born in Germany to Ghanaian parents, Westendorf moved over to England at the age of 13 and spent last term plying his trade for Isthmian League North Division side Barking FC, who compete in the eighth tier of English football.
After his successful trial with the Magpies resulted in a maiden professional deal, Westendorf admitted he is enjoying his new surroundings as well as relishing the challenges he faces in comparison to his non-league background.
"I was playing for Barking last season, playing mens' football," the Bremen-born youngster added. "I then got a call from my agent saying that Newcastle were interested. I came up, did well, and from there I told him I wanted to sign for Newcastle.
"It's a brilliant city with nice people and I'm looking forward to the future.
"I'm living quite far away from Barking but this is my dream. You have to sacrifice things. I've left my friends and family behind but, ultimately, I want to be a footballer. I think Newcastle is a big opportunity for me to develop as a player.
"It's tough but I'm happy at the same time. Everyone is nice there and it's a big step. It's new for me going from training twice a week to full-time. It's different but I'm looking forward to it and feel like I'm getting sharper everyday.
"It's completely different playing mens' football. It's more direct with little tricks in getting held or grabbed. It's more physical but I think that's a reason why I'm here - to help the younger ones. I'm happy to make a step from mens' football to under-23 level and let's see what happens."
