The midfielder, who joined the Magpies on a four-year contract last month, hadn't played in the top flight since playing 89 minutes for previous club Burnley in a 1-1 draw with Tottenham Hotspur in early March, and his only competitive appearance between then and this weekend came in Ireland's UEFA Nations League clash with Bulgaria last week.
But it was testament to the Dubliner's fitness that he played the full 90 minutes at the London Stadium - having also played the whole game in Sofia just over a week previously - while he showed his quality with two key moments in an impressive overall display on the right-hand side of the Magpies' midfield.
Speaking after his first top flight appearance in more than six months, Hendrick told nufc.co.uk: "It was a longer wait than I would have liked but the main thing was coming here, starting the season off well, getting three points and putting a solid performance in, which I think all the lads did.
"First of all (the plan) was to make it hard for them - the main priority in football is to work hard and give everything. I think that's what everyone did, even the subs coming on, and then when you get chances try and take them - and thankfully we did.
"I think both teams had chances and in the first half, maybe going in 0-0 was right; they hit the crossbar but we created a few chances ourselves and on another day some of them would have gone in.
"But we said at half time, keep digging deep and we'll get our chances. And we did, and we took them."
Hendrick set up Callum Wilson's opener in the 56th minute with a headed flick to divert Javier Manquillo's right-wing cross into the path of his fellow debutant.
"We said at half time with me coming inside, Manqy's on all day and it was a nice bit of work from him to get the cross away," he explained. "(It took) a little deflection, and for me it was just trying to help it into the danger area and Callum was alive and put it away."
Then three minutes from time, Hendrick put the seal on the win and his own display with a fine debut goal. The 28-year-old told NUFC TV on his first day at the club that he was determined to add more goals to his game, and he started as he clearly means to go on at the weekend.
"I told you it's something I'm working on and I want to keep doing. I was trying to get in the back post when I was on the other side, and get in and around the box, and I was calling Miggy for the ball. He heard me and picked me out, and it went in. On another day it maybe goes over the bar but I'm thankful it went in."
It was a powerful strike from the just inside the box which flew into the top corner, but when asked if it was one of the best goals he has scored, Hendrick smiled: "I don't want to big myself but I've scored a few nice ones!
"But I'm happy to get the win in the first game with the lads, and get a goal. It's a brilliant feeling. Getting three points on the first day of the season is massive and it's something we can build on."
