(CNN) -- Pakistan captain Shahid Afridi announced his retirement from Test cricket after his side slumped to a 150-run defeat to Australia at Lord's on Friday.
It was a thumping victory for Australia in the first Test of a two-match series, being held in England because of the security situation in Pakistan.
Afridi, who was dismissed for two runs in the second innings, revealed his decision in the post-match interview, saying he no longer had the temperament required for the longest form of the game.
"I've not been fully fit with a side strain and so I will not play Test cricket after the match in Leeds," Afridi told gathered reporters.
Afridi, nicknamed "Boom Boom" because of his big-hitting exploits in one-day and Twenty20 cricket, had only just returned to the Test arena after a four-year absence to take over the captaincy of a youthful Pakistan side.
He had been criticized for his carefree tactics in the first innings, hitting 31 in quick fire time before attempting one big hit too many and being caught.
Pakistan, chasing a world record fourth innings victory total of 440, were bowled out for 289, with Salman Butt, who is likely to replace Afridi as Test captain, top scoring with 92.
When he was dismissed by part-time off spinner Marcus North, the Pakistan effort faltered.
North eventually finished with a six wickets for 55 runs -- with Afridi one of his victims -- as well as promising young middle-order batsman Umar Akmal.
It was Australia's 13th straight Test win over Pakistan.
The second Test starts at Headingley next Wednesday which is set to be Afridi's farewell.
Yawar Saeed, the Pakistan tour manager, told AFP: "Yes, he has told us he is not feeling comfortable with the injury and has told us he doesn't want to play (Tests) but we will talk to him and then decide."
Pakistan have been forced to play their international cricket abroad since gunmen attacked a coach carrying the Sri Lanka team at a Test match in Lahore in March 2009.