Jermain Defoe’s stunning first-half volley was enough for Sunderland to move three points clear of the Premier League relegation zone, but Advocaat felt his side’s hard work was the difference between the two sides.
“It was working from the beginning to the end,” Advocaat told Sky Sports.
“You could see at the end we were a little bit tired. We couldn’t control it anymore and then they started playing the high ball, but overall I think it was a well-deserved win for Sunderland.
“The way we worked, the way we played. I’m really proud of them.”
On a weekend of special goals in the Premier League, Advocaat was full of praise for Defoe’s brilliant strike, but was quick to praise the efforts of Steven Fletcher and Connor Wickham in the 1-0 victory.
“It was a brilliant goal,” the Dutchman added. “Besides that we had plenty of opportunities to score more goals. We gave one chance away but overall I thought we deserved it.
“Last week he (Defoe) couldn’t train because of a hamstring problem but he worked today. All three front players did really well.
“If they play well then it is much easier for the midfield. Everybody did their task and I’m really happy.”
Finally, Advocaat, taking charge of his first game at the Stadium of Light, paid tribute to the Sunderland fans and the atmosphere they created during the match.
He said: “When we arrived on the bus the fans were really excited.
“I’ve said it before but if you can get them behind you – and that happened right from the start – that can give you an extra boost.
“The fans really were the 12th man and I’m pleased about that. If we keep playing like this we will give every opponent a very difficult time.
“We know we’ve still got three home games to go and we have to get the points there as well. Every game is important. We now start concentrating on the next one which is Crystal Palace.
“I’m really happy for the players and the fans because they deserve it.”