First he scored the opening goal in Monday night's 3-1 win over Mexico with a header from a corner. Then he completed the full 90 minutes on Wembley's heavy pitch to prove his fitness.
For someone whose international career seemed to be at an end when he was called up for the matches against Slovakia and Ukraine 15 months ago but released without so much as completing a training session, just pulling on the England shirt for the 20th time was a major achievement.
King said: "It's been a long time coming. I didn't know whether I would play again for England and it makes it all worthwhile.
"I wouldn't say it was one of my best games but it was tough because Mexico are a good side."
However, King has much more to aim for.
England manager Fabio Capello will now rest him for Sunday's final warm-up match against Japan in Graz.
But it seems certain King will be part of the 23-man squad Capello unveils on June 1, and the 29-year-old is certain his body can cope with the demands of a five-week tournament.
He said: "With the knee I'm confident. This season I've had problems with the muscle but I've put that behind me now and got games under my belt.
"I played three games in the last week of the season so it proves I can do it and can play games in quick succession. And the Wembley pitch was quite energy sapping.
"The more I play the fitter I get, and the medical staff are doing a brilliant job to help me prepare for the games.
"I will try to be as fit as I can and we'll see where it goes."