Kevin Pietersen said he "got goose bumps" when told he had been preferred to Graham Thorpe for next week's first Test against Australia.
"It was a special feeling - I'm as delighted as you can get," said the Hampshire batsman.
"They are big shoes to fill - Thorpey is a great cricketer for England and could be still great.
"This is an opportunity for me to cement my place in the England side and reward people for selecting me."
Pietersen said he believed his 74 in Tuesday's final one-day match against Australia tipped the balance in his favour.
"I put pressure on myself and for the first time I was really nervous," he continued.
"The only difference between Tuesday and next Thursday is that it's a different kind of ball.
"I just play my natural game. If it comes off, it comes off and if not then hopefully I'll get another go."
Thorpe said he was disappointed at being left out of the Test squad but in a statement on the Surrey website made no comment on his England future.
"I am disappointed not to be selected in Ashes squad, but I respect and understand the selectors decision," he said.
"I wish Michael Vaughan and the England players all the best for the opening Ashes Test at Lords.
"I am happy with my form and fitness and I am looking forward to playing a key role for Surrey as we approach an important stage in the season."
Australian opening batsman Justin Langer said England will miss Graham Thorpe but believes Kevin Pietersen will be a Test success.
"Graham Thorpe has played 100 Test matches for England and they're definitely going to miss that kind of experience," said Langer.
"I'd also say Graham's been one of England's most consistently reliable performers against Australia."
"But Pietersen has got an excellent first-class record and I'm sure he'll have no problems adapting to Tests."