The defending champions were rarely tested as Offaly failed to fire in front of 77,623 spectators.

Offaly were 0-5 to 0-0 behind before Niall McNamee, who top-scored with 0-7, opened his account in the 19th-minute. Mark Vaughan was on target twice as Dublin led 0-6 to 0-2 at half-time.

Poor shooting blighted the game which was effectively decided in the 37th-minute when Offaly defender Joe Quinn, under pressure from Vaughan, unfortunately directed the ball into his own net.

Not for the first time, Offaly were caught out by a lack of firepower and grunt up front against Dublin. Before today's game, the Faithfuls had averaged just under 10 points against Dublin in the counties' previous five championship meetings, including only one goal.

Against that, the Dubs had average 17.6 points and while Paul Caffrey's men should certainly have scored more than they did by the final whistle, you always got the sense that there was only going to be one winner.

Having accounted for Carlow last time out, Offaly had plenty to fight for - revenge for last year's Leinster final defeat and a place in the 2007 decider against either Laois or Wexford.

The fact that the start was delayed by 15 minutes, due to the large swathes of supporters coming through the gates, seemed to have more of an affect on Pat Roe's men.

Offaly made a sluggish start, were second to a lot of break balls in the opening 20 minutes and allowed Dublin too much time and space to take their scores.

Defenders James Keane and Scott Brady were both badly caught out as Dublin strode into the five-point lead. Mossie Quinn, Vaughan, Alan Brogan and Conal Keaney each pointed before former captain Ciaran Whelan launched over one of his trademark scores to the delight of the blue-shirted hordes.

Both sides had altered their starting line-ups before the throw-in with Bernard Brogan replacing dual star Diarmuid Connolly in the Dublin attack, and Offaly included Conor Evans for knee injury victim Ger Rafferty at right corner back.

Injury struck again for the Faithfuls in the 14th-minute when they lost influential forward Thomas Deehan to a hamstring injury.

Offaly's forwards, particularly full-forward PJ Ward who was well chaperoned throughout by Ross McConnell, were struggling to make an imprint on the game but McNamee's 19th-minute did at least get the underdogs off the mark.

Vaughan replied for the Dubs who then went through a barren spell as Offaly grappled well for their share of possession and watched McNamee crack over from play in the 27th-minute after fending off Paul Griffin.

That proved to be the final score of an attritional first half during which the Dubs hit seven wides to Offaly's six.

A quick point from Niall Smith got Offaly off to a satisfying start in the second half, but barely a minute later the ball was nestling in their net.

The Dubs moved 1-6 to 0-3 ahead when Brogan broke free and fisted the ball over the advancing Padraig Kelly who could only watch as full-back Quinn touched the ball into his net as Vaughan closed in.

Points from Brogan and Vaughan saw Caffrey's men move further ahead, with wing back Paul McConway conjuring up a neat score at the other end.

There was a rather listless finish to the game as after Dublin had raised four more white flags, Caffrey's men failed to kill off their opponents.

The tempo dropped and had Offaly snuffed out a goal - they also did when substitute Sean Ryan crashed a 47th-minute shot off the crossbar - the Metropolitans may have been in for a fright.

Offaly succeeded in scoring four points in the game's final six minutes to cut the gap to five, but not even experienced goal-getter Ciaran McManus could test Dublin stopper Stephen Cluxton with a serious shot.

It was a case of job done for Dublin, most of the positives were in defence where McConnell, who only made his championship debut recently, was particularly solid and Caffrey who now has three weeks to sharpen up his panel before the Leinster final.

For Offaly there will be little consolation in their entry now into the Tommy Murphy Cup. Players like Niall McNamee, McManus and Karol Slattery should be featuring in the All-Ireland qualifiers, but collectively Offaly disappointed today in what was their eighth successive championship defeat to Dublin since 1982.

DUBLIN: S Cluxton; D Henry, R McConnell, P Griffin; P Casey, B Cullen, B Cahill; C Whelan (0-1), S Ryan; C Moran (capt) (0-1), M Vaughan (0-3, 0-1f, 1 '45'), B Brogan; A Brogan (1-2), C Keaney (0-3, 0-1f), T Quinn (0-1).

Subs used: J Sherlock (0-1) for B Brogan (44 mins), R Cosgrove for Quinn (54), C Goggins for Casey (61), D Magee for Whelan (65), D Lally for Moran (69).

OFFALY: P Kelly; C Evans, J Quinn, J Keane; P McConway (0-1), S Brady, K Slattery; A McNamee, N Smith (0-1); N Coughlan, P Kellaghan, C McManus; T Deehan, PJ Ward, N McNamee (0-7, 0-4f).

Subs used: S Ryan (0-1) for T Deehan (17 mins), R O'Connor for Smith (47), J Coughlan for Ward (50), W Mulhall for Kellaghan (65), S Sullivan for Slattery (70).

Referee: Michael Collins (Cork)