After Australia beat Pakistan by 150 runs in the first Test at Lord's Afridi said the second and final match, starting at Headingley on July 21 would be his last.
Marcus North took six for 55 to join team mate Shane Watson on the Lord's bowling honours board, a pairing nobody could have predicted when the first match in a two-Test series started on Tuesday.
His figures were the best ever returned by an Australian spinner at Lord's.
Pakistan, set a record 440 to win, succumbed for 289 before tea on the fourth day to extend a miserable losing streak which started in 1999.
"I did the wrong thing. I think my temperament is not good enough for Test cricket and I am struggling with a side injury. I think maybe the next Test will be my last," Afridi told BBC Radio after the match.
"It is a board decision but I would think Salman Butt is the best man for the job now. I have a bit of an injury and I would rather focus on one-day and Twenty20 cricket," said Afridi, who played his first Test in four years.
His decision means a new captain will be in place when Pakistan take on England in the four-Test series starting on July 29.
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