World Cup holder Australia struggled to post 262-6 against unfancied Zimbabwe's spin bowlers in their Group A match at Sardar Patel Stadium on Monday.

The champion began its title defense in stuttering fashion, despite half-centuries from in-form opener Shane Watson and Michael Clarke.

Watson hit 79 and Clarke was 58 not out, but the Aussie batsmen struggled with the lack of pace on the Ahmadabad pitch and never found top gear.

Brad Haddin crawled to 29 off 66 balls before he was lbw to Prosper Utseya and Watson fell to another slow bowler, legspinner Graeme Cremer.

Captain Ricky Ponting was run out for 28 in his record 40th World Cup match, without hitting a boundary, before Clarke lifted Australia to a respectable, but not impressive, total.