The defender is set to make a 166th appearance for his boyhood club at the Amex Stadium on Saturday, having become a key figure under Rafa Benítez; six years ago, he had impressed on loan at Gateshead and St. Mirren and was handed his Magpies bow by Alan Pardew, but United lost 2-0 to the Seagulls, who were a Championship club at the time.
Albion still have work to do to ensure they don't return to that division next season, but Newcastle have already secured their top flight safety and that has given Dummett an opportunity to reflect on where it all began.
"I came on as a sub in that game, when we were losing, and I think you look back sometimes and you probably never thought I'd be at the stage I am with Newcastle now, playing the amount of games I've played," the now 27-year-old told nufc.co.uk.
"Obviously it was a learning experience, playing in that game - we got a bit of a runaround in the game - but we've played against them quite a lot since.
"We did well against Brighton in the Championship and they're still in the relegation fight, so they'll be nervy and desperate for the three points.
"Cardiff are right behind them, breathing down their necks. We can probably play with a bit of freedom, knowing that we're safe, and hopefully that can bring a better performance from us.
"Hopefully they'll feel the pressure at home in front of their fans, so we'll be going there to try and get the three points and finish in a good position in the league."
Since that maiden appearance on the South Coast - Dummett still has his maroon shirt from the day in a frame - the Academy product has gone on to captain Newcastle several times, play more than a century of games in the top flight and win full international honours with Wales.
But while the majority of his appearances have been as a left back, in recent weeks Dummett has found himself playing on the left of a three-man central defence.
It's a position many have long felt he would be well-suited to and he admitted: "I do enjoy it - it's obviously a bit in between centre back and left back.
"The role I play when I do play left back is a bit more defensive than offensive so I think the position suits me really well, especially being left-footed, and it gives us a good balance in the team.
"As long as the manager's going to play this formation, I'm going to have to keep on learning the role and the position, and what he wants from me in that role.
"I have enjoyed putting in some decent performances and it was nice to get in Alan Shearer's Premier League team of the week last weekend.
"It does give you an advantage being able to play in different positions along the back line - if I need to play at left back or left centre back or left wing back, I can fill in any of those roles really."
Although Florian Lejeune has now been ruled out for the rest of the season, Benítez still has Fabian Schär, Federico Fernández, Ciaran Clark and skipper Jamaal Lascelles vying for a centre-back place as well as Dummett, who admitted: "We've got six centre-halves for three positions, really, so we are strong in that sense.
"There is competition but I think every squad needs competition and it brings out the best in players because you know if you don't play well, you could be out and if another player comes in and plays well, you're stuck on the bench.
"It's good that everyone's fighting to play and that's key to getting the best out of players and doing well on the pitch."
