The result throws Group B, which includes India, the West Indies and South Africa, wide open.  [AFP]

Ireland’s Kevin O’Brien smashed the fastest century in Cricket World Cup history off only 50 balls to give his team an almost-unbelievable three-wicket win over England on Wednesday.

The result is one of the biggest upsets in the tournament’s history, and is Ireland’s greatest ever win on the world stage.

O'Brien came to the crease with Ireland struggling on 106 for four chasing a mammoth 327 for eight in Bangalore and ripped through the England attack, striking six sixes and 13 fours. It was the highest successful run chase in the tournament.

He also smashed Matthew Hayden's record for the quickest World Cup century on the way.

O'Brien was run out in the penultimate over but his sixth-wicket stand of 162 with Alex Cusack effectively clinched the Group B match for a win even more memorable than Ireland's victories against Pakistan and Bangladesh at the last World Cup.

Nothing boring

"When you are 111-5 I just said to myself, we could just potter around and get 220 off 50 overs for eight or nine and the game would have been pretty boring to watch and it wouldn't have been anything to watch on TV," a grinning O'Brien said clutching his man of the match trophy.

"I just chanced my arm and said I'm going to be as positive as I can and I got a few away and didn't look back really."

The 26-year-old O'Brien dismantled the English bowling to score 113 runs in 63 balls and his knock helped produce the first upset in this year's showpiece.

He was run-out - the only way he could fall - with 11 runs still required off as many balls.

However, John Mooney (33 off 30 balls) kept his head and with three required to win off the last over, smashed a boundary to spark off the Irish celebrations.

Ireland's victory throws Group B, which includes India, West Indies and South Africa, wide open.

O'Brien came to the crease with almost half his side back in the pavilion in the 23rd over.

scorecard

England innings
A Strauss b Dockrell 34
K Pietersen c O'Brien b Stirling 59
J Trott b Mooney 92
I Bell c Stirling b Mooney 81
P Collingwood c K O'Brien b Mooney 16
M Prior b Johnston 6
T Bresnan c Johnston b Mooney 4
M Yardy b Johnston 3
G Swann not out 9
Extras: 23
Total: (8 wickets; 50 overs) 327
Fall of wickets: 1-91 2-111 3-278 4-288 5-299 6-312 7-317 8-327

Ireland innings
W Porterfield b Anderson 0
P Stirling c Pietersen b Bresnan 32
E Joyce st Prior b Swann 32
N O'Brien b Swann 29
G Wilson lbw b Swann 3
K O'Brien run out 113
A Cusack run out 47
J Mooney not out 33
D Johnston not out 7
Extras (b 5 lb 16 w 12) 33
Total (7 wickets; 49.1 overs) 329
Fall of wickets: 1-0 2-62 3-103 4-106 5-111 6-273 7-317

He then turned on a breath-taking show of power hitting while the M. Chinnaswamy Stadium roared him on.

Inspired by O'Brien, Alex Cusak smashed 47 runs as they put on 162 runs for the sixth wicket before he was run out with Ireland still requiring 55 runs to win.

However, O'Brien soldiered on and no amount of bowling changes or field placings could stop him and England came loose at the seams with misfields and dropped catches aiding Ireland's chase.

England will rue four dropped catches, including captain Andrew Strauss's spill of a skied shot when O'Brien was on 91. Matt Prior spilled a high catch from Ed Joyce, James Anderson let a shot by Niall O'Brien sail through his hands on the boundary for six and Michael Yardy dropped Cusack on 32 off his own bowling.

England falter

England had looked in total control earlier after Jonathan Trott hit 92 and Anderson bowled Ireland captain William Porterfield with the first ball of the Irish reply. Swann took three wickets in 13 balls to make it 111-5 but that was as good as it got for England.

Trott and Ian Bell added 167 for England's third wicket, with Trott equalling the record set by Viv Richards and matched by Kevin Pietersen for the quickest ever 1,000 one-day international runs, reaching the mark in 21 innings.

Bell struck 81 and Pietersen chipped in with 59 as England looked to have justified Strauss' decision to bat after winning the toss.

England could have set an even bigger target, but slipped from 278-2 to 327-8. After early struggles, Trent Johnston finished with figures of 2-58 becoming the first Ireland player to take 50 one-day wickets, and Mooney had Tim Bresnan caught off the last ball of the 50 overs to finish with one-day best figures of 4-63.

Devastated England skipper Andrew Strauss said England's poor showing in the field had cost them.

"We thought we'd done a reasonable job with the bat and we got Ireland at five down and things were looking pretty comfortable," he said.

"But we weren't reckoning on an outstanding innings from Kevin O'Brien. It was pretty brutal."

He was at a loss to explain the poor fielding, adding: "We put down another three or four catches and in the end that cost us the game."

Source: Agencies