The goalkeeper impressed on his debut against Manchester United earlier this month.
Dubravka, signed on loan from Sparta Prague, kept a clean sheet in a 1-0 win for Rafa Benitez’s side.
The 29-year-old made a string of saves to keep Jose Mourinho’s side at bay.
The result, the club’s first home win in almost four months, took the relegation-threatened club up to 13th in the Premier League table.
Dubravka, determined to seize his “big opportunity” at St James’s Park, is now focused on Saturday’s game against Bournemouth at the Vitality Stadium.
United are three points behind Eddie Howe’s 10th-placed side.
“It was a big opportunity for me to come to this big club with great history and very good players,” said Dubravka.
“I was very happy and very satisfied that I could compete with the best players in the Premier League.
“Now I’m here and trying to get used to it.”
Dubraka was picked against Man United ahead of Karl Darlow, who had started the club’s previous seven league and cup games.
Benitez – who moved for Dubravka after failing to sign 36-year-old free agent Willy Caballero last summer – also has Rob Elliot available to him.
Elliot, handed the No 1 jersey by Benitez last summer, has recovered from the thigh problem he suffered in late December.
Dubravka – who made a superb save with his left leg to deny Man United’s Anthony Martial with the score still goalless – is looking to turn his loan into a permanent move at the end of the season.
“It’s exciting to be here, it is a big club particularly in my own country,” said the Slovakia international, who played against England in a World Cup qualifier at Wembley early this season.
“I appreciate the opportunity, and I will try to do my best to stay. Hopefully, it will not just be a loan.
“I really hope I get to stay longer than six months. It’s a huge opportunity for my life.”