The pre-season favourites stuttered towards the finishing line, allowing Huddersfield to make the race for automatic promotion interesting as the season reached its conclusion.
But a 4-1 thrashing of 10-man Preston confirmed Rafael Benitez's men would be returning to the top flight at the first opportunity.
Ritchie, whose penalty added to Ayoze Perez's double and a Christian Atsu strike, now has his eyes on going up as Championship winners, with leaders Brighton four points ahead with two games left.
"It's been a bit tense but the lads always believed," Ritchie told Sky Sports.
"We are disappointed we are not top given where we were a few weeks ago but we can only affect what we can now. Hopefully we can win on Friday and put Brighton under pressure."
Preston had threatened to spoil the party at St James' Park when Jordan Hugill cancelled out Perez's opener, but Paul Gallagher's red card for handling the ball on the goalline, which allowed Ritchie to make it 3-1 from the spot, ensured the celebrations could start.
Skipper Jamaal Lascelles said: "(It was an) excellent performance. I'm so proud of the boys this season.
"The fans have been unbelievable. They've stuck by us - it's overwhelming to be honest."
Lascelles also has his eyes on silverware.
He added: "Of course (the title) matters. That's what we're going to go for.
"The main aim was to get back into the Premier League, that's what we've done, but of course it'd be nice to overtake Brighton. We'll see how the next game goes and hopefully we can overtake them and win the title."