Potchefstroom(South Africa),Feb 28: Glenn McGrath produced the best-ever bowling figures in a World Cup as Australia registered the biggest victory in one-day history against Namibia here Thursday to become the first team to reach the Super Six. McGrath's 7-15 from seven overs improved upon the 7-51 taken by West Indies' Winston Davis in 1975 as Namibia were skittled out for a mere 45 runs in 14 overs in reply to Australia's 301 for six . The 256-run margin, which saw Australia extending their winning run to a record 11 consecutive matches, was the biggest in one-day history, bettering the 245-run defeat Sri Lanka had inflicted on India in Sharjah in 2001. The win guaranteed the defending champions a place in the Super Six from group-A. They have won all their five matches so far, accumulating 20 points, and have a game against England left. Bureau Report