By Scott Heinrich BBC Sport at Edgbaston

They say contests between India and Pakistan have to be seen to be believed.

Match photos from Edgbaston

Grudge matches don't get much more personal than this, and Birmingham had the honour of staging the latest battle between the two cricketing giants.

Ten minutes inside the ground was all it took for me to wonder if this was the same tournament which had dragged its heels through the opening week.

Bad weather, one-sided matches and poor attendances had put a question mark over the event the International Cricket Council like to call the mini World Cup.

Under dreary skies, Edgbaston had resembled a ghost town as fans snubbed early group games like England v Zimbabwe and South Africa v Bangladesh.

But suddenly the ground was transformed, packed to the brim with two sets of fans who can lay claim to being the most passionate in the world.

Even the weather was alert to the occasion. Make no mistake, this was the day the Champions Trophy came to life.

Never before have I seen singles cheered with such fervour, wides and no-balls derided with such heartfelt rancour.

There was a visible police presence around the ground, but from my standpoint they were not needed. These people came to watch cricket.

The struggle for supremacy in the middle was being acted out in the stands, with opposing fans competing for their voices to be heard and their colours to be seen.

India's supporters tried to revive their team

The ubiquitous hum around the ground - a cacophony of horns, whistles and shouts - built up to a crescendo as the bowlers charged in to deliver.

It seemed Indian fans outnumbered Pakistanis, but the latter made up the difference in noise.

The loss of early wickets - including the India captain Sourav Ganguly for a duck in the first over - sent the green contingent into a frenzy.

But the Indian supporters were only ever a square cut or mis-field away from rapture, and they rarely quietened down even during the 101 balls that passed without a boundary in mid-innings,

The introduction of fast bowler Shoaib Akhtar in the 16th over evoked the most deafening response of the morning.

A star in Pakistan, Shoaib is by default a villain in India - and there was no way either set of fans were going to let a chance to vent their feelings pass them by.

I'm told the atmosphere is like this every time India and Pakistan play, which makes me wonder how the players manage to concentrate when they are met with silence during games against other teams.

Australia versus England at Lord's, the Ryder Cup between USA and Europe, Argentina against Brazil in football; these are all contests which set the pulse racing.

But there is something special, something decidedly unique, about a game of cricket between India and Pakistan.

They say these matches are more than just sport, and on an astonishing day in the heart of England I believed them.