Defoe replaced the Dutch ace before netting superbly.
"Jermain scored a great goal and at that moment I thought we were going to win the game. Newcastle scored a good equaliser, and that was a pity," Van der Vaart told the Spurs website.
"It was a good opportunity to win and get above Newcastle, but in the end perhaps it was a fair result.
"The next league game is Blackburn and we'll be looking to get the three points again."
As for his penalty, Van der Vaart added: "There is always pressure when you take a penalty and I'm glad it went in because the goalkeeper is a Dutchman and he knows me well. I was happy to see it go in."