World Cup History: Five instances when the tournament champion had a 100% win percentage 

#4 Australia - 2007

ICC Cricket World Cup Final - Australia v Sri Lanka

Three time champions Australia had built an undefeated streak in the World Cups and every team of the world feared playing the Australian team especially in the World Cups. In the first ever World Cup hosted by West Indies, defending champions Australia had a smooth run in the group stage where they bulldozed Scotland, Netherlands and South Africa.

In the Super 8 stage, Sri Lanka, New Zealand, South Africa, England, West Indies, Ireland and Bangladesh tried to defeat Australia in their respective matches but none of them succeeded.

First placed Australia decimated the fourth placed South Africa by handing them a 7-wicket loss in the semifinals before winning the final against Sri Lanka by 53 runs. Australia became the second team in World Cup history to win two consecutive World Cups with a win percentage of 100.