Defoe convinced Portsmouth can shock Chelsea
"It's not an easy place to go to but we can take a lot of good things from the Community Shield last week.
"If we can go there and work hard like we did against Manchester United then I think we can get a result."
Slated for their penalty shoot-out performance in last weekend's Community Shield at Wembley - Defoe was their only scorer from the spot - as United triumphed 3-1, Pompey's players are still proud of their performance in denying the Premier League and European champions a goal in open play.
Defoe said: "We can improve attacking-wise from last week, but we defended really well then and need to do that again."