Spurs needed a late equaliser from Gylfi Sigurdsson to snatch a 2-2 draw and keep their hopes of a top-four finish ticking over.
But Andre Villas-Boas' men are now level on points with Chelsea and just two ahead of Arsenal, having played a game more than both their London rivals, and Holtby knows there is a lot of work still to do.
The German midfielder is looking forward to the rest of the season and has called on his team-mates to rise to the challenge.
"At the end of the day, if we want to play in the Champions League we want to win games like these," said Holtby.
"But we've still got decisive games against City at home and against Chelsea away, which are going to be big games.
"The games against Southampton and Sunderland are also ones we have to win to get those points to stay up there in the top four.
"I'm confident that we can do it because we have a lot of quality in our side."