The 18-year-old winger, who joined Newcastle's Academy in 2019, was one of a number of United youngsters handed a senior bow against the Tigers, with the teenager appearing in the latter stages at the MKM Stadium.
Born in Carlisle, but a representative of Scotland at under-19 level, Emerson expressed his delight in achieving a childhood dream and is now keen to build on his maiden outing.
Emerson, who signed his first professional contract with United last month, told newcastleunited.com: "It was one of the best feelings of my life when I came onto the pitch and the crowd were cheering. To play for Newcastle's first-team in front of 4,500 away fans was an unreal experience, especially with all of my family watching too, so I was proud.
"You're hoping to get the call to come on so you're on your toes waiting for it. When it happened, I was excited with a little bit of nerves but I felt confident as soon as I stepped onto the pitch and loved it.
"It made it easier being alongside the lads I've played with at the Academy for a few years, improving and progressing as a player and person with. To do it together with them was good.
"It's been a long but short five years at the club, with lots of ups and downs, but it all felt worth it when I came onto the pitch. I didn't want the game to end. When the whistle blew, I was disappointed because I was starting to get a lot of the ball and enjoying myself.
"After that, I feel really motivated to try and get back into that position again."
The Magpies' under-21 side are in friendly action on Sunday, 4th August when facing South Shields at the 1st Cloud Arena but have been in Spain this week, completing a warm weather training camp in Pinatar.
Emerson believes the trip abroad has proved a beneficial one ahead of the commencing of the 2024/25 season facing and is relishing the clash against the National League North outfit.
"It's been good in Pinatar," Emerson added. "I think training in this heat tests us but it's also good for being part of a group. We've known each other a while as some of us played up an age group last season but training here and bonding together as a team helps us both on and off the pitch.
"Especially now, with a lot of new players signing and younger players coming through, the trip has been beneficial for them getting integrated into the group.
"We know it'll be a tough test with South Shields being a senior team and we're quite a young under-21s side. It's a test we need going into the season and I'm excited for it as I missed a lot of the second half of last season and, since then, I've wanted to start playing football again."
