Murphy set up Ayoze Perez's winner in yesterday's 1-0 win over Stoke City at the bet365 Stadium.
It was Murphy's first Premier League assist for the club, which is now 13th in the division.
The 22-year-old joined Newcastle from Norwich City last summer in a £12million deal.
And Murphy had his best game for the club against Stoke.
United manager Rafa Benitez gave his verdict on Murphy after the game.
And Murphy has spoken about his start to the New Year.
“It was the perfect way to start the year," said Murphy. "I’m over the moon to start 2018 with my first Premier League assist for Newcastle – I couldn’t think of a better way to do it."
Murphy says he's more "relaxed" going into games now he's settled at the club.
And, game by game, he's growing in confidence.
“This is just the start," said Murphy. "I can’t get too ahead of myself after just setting up one goal, but I’ll keep working hard and pushing forward to create more chances for the boys.
“I’m a lot more relaxed going into games now, I’m feeling less pressure, and I can go out there and play my own game.
"I’m a confidence player, and you need that confidence to go into games and do what you want to do.”
Murphy was given a standing ovation by the club's 3,168 travelling fans at the bet365 Stadium.
“I was buzzing with that,” Murphy told the club's official website. “I’ve been smiling ever since I got into the dressing room, and the lads are buzzing for me as well. I’m delighted.”