The 29-year-old fired a powerful effort past Gianluigi Buffon in the 79th minute, after Daniele De Rossi and Phil Jagielka had both scored from corners in the first half.
“It was one of my best and I would like to dedicate that goal to my cousin who died in St Lucia, it would have been their birthday today,” said Defoe.
“It was nice to come on and score but it was important to get a win so it was good.
“I think even if you speak to the lads with more caps than me they still want to prove themselves everytime they pull on an England shirt and prove things to the nation and to the manager.
“I’m always looking to prove things. Every time I play I give 100 per cent and as a striker I am judged on goals and it is always nice to score for your country.”
Manchester United’s Tom Cleverley, who made his England debut against the four-time World Cup winners, believes his experience with Stuart Pearce’s Team GB side at the London 2012 Olympics is already proving beneficial.
“It was a proud moment, and obviously a big occasion in any footballer’s life,” said Cleverley.
“I managed to get on the ball a few times, they made it hard for me in there and came in with some hard tackles and De Rossi is a good player but hopefully I have impressed the manager and can be called up again.
“I felt we looked after the ball today, we controlled the game in light spells and I knew my role. I played there against Senegal for Team GB in the Olympics, so I know the role well and I enjoyed it.”
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