Four key Trophy matches](BBC SPORT | Cricket | Champions Trophy | Four key Trophy matches)
The world’s top teams play 12 group matches over nine days to decide the ICC Champions Trophy semi-finalists.
But, if there are no major upsets, the top teams will emerge from four key games played at the end of the pool stage.
**Australia v New Zealand, The Oval, 16 September **
The rivalry between Australia and New Zealand is always tense
For the second time running in this tournament, the result of the Trans-Tasman clash will decide the outcome of Group A, which this time also features USA.
In Sri Lanka in 2002, Australia proved too strong, racking up 296-7 and then bowling New Zealand out for 132, with Glenn McGrath claiming five wickets.
The Black Caps will use that as motivation against their arch-rivals, while Australia are focused on the fact they have never won this tournament.
Despite that, the world champions are favourites for the title with a settled side that combines their best Test batsmen and veteran bowlers with a handful of one-day specialists.
New Zealand won this year’s NatWest Series - England’s annual one-day tournament - with a team that specialises in the one-day game, batting right down the order.
**Sri Lanka v England, The Rose Bowl, 17 September **
England have been forced to rethink their one-day plan
Joint-champions in 2002 after a washed out final, Sri Lanka will find it far tougher in English late-season conditions.
But with the third side in Group D, Zimbabwe, under strength after their recent player row, Marvan Atapattu’s team pose the biggest threat to England’s ambitions.
A younger side, their search for a pace bowler to partner Chaminda Vaas has been helped with the arrival of Lasith Malinga and return to fitness of Nuwan Zoysa.
Missing from the line-up, though, will be star spinner Muttiah Muralitharan, who has recently undergone shoulder surgery.
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England were forced to rethink their approach to one-day internationals after a poor summer but the focus will still be on big-hitting all-rounder Andrew Flintoff.
**South Africa v West Indies, The Oval , 18 September **
Lara lit up the World Cup opener against South Africa
Politics kept them apart until 1992 but these two sides have played some classic one-day contests since, and are both likely to overwhelm group-mates Bangladesh.
This fixture formed the inaugural final and was a highlight of the group stages of the last Champions Trophy, South Africa scraping to a two-wicket win off the final ball of the match.
And they met again in the opening match of the 2003 World Cup, when Brian Lara’s century inspired the Caribbean side to upset a confident home side.
In woeful Test form, West Indies can call on some veteran bowlers to bolster their one-day performance and have spent much of the summer in England.
South Africa have struggled in their last two series with their bowlers, Shaun Pollock apart, struggling to stop sides scoring quickly.
**India v Pakistan, Edgbaston, 19 September **
Partisan fans will be out in force at Edgbaston
It does not matter how often these two side play, this will still be the most eagerly anticipated contest in one-day international cricket.
The UK last got a demonstration during the 1999 World Cup, when a packed Old Trafford saw India win a second round match by 47 runs, although Pakistan went on to reach the final.
Since diplomatic relations thawed earlier this year they have played seven ODIs, with Pakistan winning four.
Form goes out of the window on these occasions but India are the better team on paper, with an experience batting line-up and green but talented pace bowlers.
Pakistan are rebuilding after an ageing side struggled in the last World Cup, but their achievements in matches against their arch-rivals this year show progress is being made.
Kenya are the unlucky third occupants of Group C, with the task of providing the appetisers for the main event.
