ON the day that the world's most famous distance race snaked through the streets of London, Middlesbrough's FA Cup marathon finally came to a shuddering halt at the hands of a team from the capital.

Playing their 58th game of a campaign that has taken them from one side of the continent to the other, the Teessiders finally hit the wall against a West Ham side who will now contest their first FA Cup final since 1980.

Visibly drained after their arduous recent workload, Steve McClaren's side were unable to stage another great escape after falling behind to Marlon Harewood's 78th-minute opener.

Thursday night's UEFA Cup semi-final second leg against Steaua Bucharest now becomes all-important in terms of salvaging their season. Win and Middlesbrough can look forward to their first European final. Lose, though, and the last nine months will be remembered for nothing more than a pair of semi-finals. It will hardly be a lasting legacy.

Despite all of their recent exertions, and Thursday's game will be their 31st since the turn of the year, it is to be hoped Boro's players still possess the energy to mount a decisive sprint finish.

Yesterday, they began brightly but faded with the finishing line in sight. Harewood's winner, driven into the roof of the net after the striker had held off Gareth Southgate, was enough to settle a game that had looked to be Middlesbrough's for the taking.

But despite dominating the opening hour, the Teessiders suffered from a lack of cohesion in front of goal and an absence of energy in a second half that gradually swung West Ham's way.

While the Football Association is expected to announce the identity of England's new manager this week, McClaren's undivided attention will be needed at Boro's Hurworth training ground. Lifting the spirits of his shell-shocked squad will not be an easy task after a narrow defeat like this.

As if the end result was not galling enough, Boro's players were also left to rue their failure to exploit an early ascendancy that was a direct result of McClaren's tactical acumen.

With Southgate, who had begun the weekend claiming his manager was too inexperienced to be named England manager, recalled as part of a five-man backline, Stewart Downing was tucked inside for the first time this season.

Jose Mourinho was lambasted for sacrificing his wingers in Saturday's semi-final but, by bolstering the centre of the Middlesbrough midfield, McClaren ensured his side would not be over-run in the same manner as Chelsea.

As a result, the Teessiders carved out four presentable openings during a frenetic first quarter and, in his new roaming role, Downing was at the heart of all of them.

His searing cross-field ball to Stuart Parnaby began a move that ended with Fabio Rochemback dragging a 20-yard shot wide and, in the tenth minute, his own long-range drive forced a smart save from former Newcastle goalkeeper Shaka Hislop.

With his ability to slip through the gears troubling both Anton Ferdinand and James Collins, Downing was the focus of Middlesbrough's attacking throughout.

It helped that he was effectively given a free role, with West Ham's defenders reluctant to push up to mark him and their midfielders occupied elsewhere.

Crucially, he was also able to drift back outside when the opportunity arose. On the few occasions when he did slip back into an orthodox left-wing role, he remained equally effective.

Pulling to the touchline, Downing's early cross found the unmarked Jimmy-Floyd Hasselbaink loitering close to the penalty spot but, while the striker's angled header was on target, it lacked the pace to beat the retreating James Collins.

Still, at least the momentum was with Boro. It remained that way for the rest of the first half, although after an action-packed opening, chances became harder to come by as the Hammers gradually adapted to their opponents' change of shape.

Franck Queudrue headed Downing's 34th-minute corner over the crossbar but, with Aiyegbeni Yakubu failing to outmuscle the imposing Danny Gabbidon and Hasselbaink lacking the pace needed to outstrip Collins, Boro's plentiful possession was largely wasted.

At the other end, their cause was hardly helped when Mark Schwarzer was forced to depart four minutes before the break. The Australian fell awkwardly after claiming a cross under pressure from Dean Ashton and left the field clutching a broken cheekbone. His participation in Thursday's UEFA Cup decider must now be in considerable doubt.

That was for the future, though. Boro's primary concern at the time of his departure was ensuring West Ham did not awake from their first-half torpor.

Given that yesterday's game was always going to make or break their season, the Hammers were strangely lethargic. Yossi Benayoun threatened to grab an undeserved opener with a 12-yard half-volley that flew narrowly over the crossbar, but West Ham's players retreated to the dressing room having been utterly outplayed in the opening period.

Their rousing return after the interval suggested Alan Pardew had warned them he was not about to stand by and watch them be similarly subservient in the second.

The previously anonymous Harewood epitomised the transformation, suddenly outmuscling Southgate to latch on to Hislop's long clearance before failing to find the target with a hurried half-volley.

Seconds later, Ashton rattled the top of the crossbar with a towering header from Benayoun's left-wing corner. The tide had turned, and Boro were in danger of being washed away.

That they weren't was largely due to yet another resilient defensive display from Southgate. Unperturbed by Harewood's physical approach, and anything but fully fit, Boro's skipper led by example as tempers began to boil.

Unfortunately, though, he was the one found wanting when West Ham finally broke the deadlock. Ashton nodded Ferdinand's long ball into Harewood's path and, after holding off Southgate, the Hammers striker lashed a rising left-foot drive into the roof of Brad Jones' net.

There was still time for Boro to salvage something, but substitute Massimo Maccarone twice failed to hit the target when the ball dropped his way in the final ten minutes.

At least, though, the Italian resembled a semblance of composure. The same could not be said for Riggott, who wasted Boro's best chance of the game in the fourth minute of stoppage time.

With the goal at his mercy following a mistake from Hayden Mullins, the centre-half dragged his snapshot well wide of the upright. Unlike the epic UEFA Cup quarter-final win over Basle, this time there was to be no last-minute let-off.