Spurs have not won at Chelsea for 21 years and face a team looking to keep their slim title hopes alive, but Defoe sees no reason why he and his team-mates cannot pull of a shock.
"It's a massive game," Defoe told Tottenham's website.
"I think they have picked it up from their little dip in form but we always play well against the top teams and I think we are good enough to go there and win.
"We are all looking forward to it and I'm sure that all the lads are confident that we can do it.”
"Every game is like a cup final so we have to just approach every game thinking we can win it," Defoe added.
"Last season it was tight but we did it. We just picked up at the right time in the last few games. We have some big games coming up against top sides again this year so let's just see what happens."
"We all think we can get fourth," Defoe said.
"This season has been special for everyone at the club.
"We have shown that we have good enough players to compete at that level.
"I missed a lot of the games through injury so for me I'm desperate to play Champions League again. It's the best competition in the world."