Ulsterman Darren Clarke took revenge on Colin Montgomerie yesterday for the #40 lost to the Scot in practice by pocketing the #125,000 winner's cheque in the Benson and Hedges International Open.

The duel between the two Ryder Cup team-mates, who began the day tied with Italian Massimo Florioli at 10-under par, never materialised over the demanding Oxfordshire course.

Clarke, who had been given a putting tip from Montgomerie during their bounce game, found his form immediately on the greens. He holed a tricky downhiller from eight feet on the first to settle any nerves following a frustrating run since his last victory in the German Masters 18 months ago.

The decisive thrust came between the fifth and seventh where he holed from 25ft, parred the next, then got up and down from a bunker where he drained a five-footer centre cup.

After having parred the short fifth, Montgomerie missed an easy uphill putt from eight feet on the next, then never threatened for an eagle although only 18ft away on the par-five seventh.

That telling burst put two shots between the pair, and Montgomerie must have known even then that it was not to be once again on a course where he has suffered so much last-day agony in the past.

By then Clarke had beaten his close friend and neighbour by five shots, shooting 67 to his 72, and gained ample reward for managing to control the fiery temper which has betrayed him so often.

Clarke, criticised by Gary Player for being overweight, said later: ''Both physically and technically there is lots of room for improvement. One major part has been missing from my game - my attitude. If I can get this right and the mental aspect results will get better. Many people have been getting on to me about my attitude but I have a very thick head.

''I was very patient this week, letting things happen instead of forcing them. Coming eighth in the US Masters definitely helped because that course is unbelievably difficult and it also required a lot of patience.

''I went out in the position I wanted to be and it was enjoyable, more so because I played really solidly. It has been a frustrating period for me because I have improved more than results have shown.

''I got my #40 back from Colin who was very complimentary, especially over the closing holes.''

Clarke, who owns a Ferrari and several other high-performance cars, would have invested his winnings on another but his wife, Heather, clamped him before the notion got going.

For Montgomerie there were again worrying signs of a deteriorating putting stroke. He could have won at Augusta last month if he had putted and he would have taken Clarke to the wire yesterday if the flat stick had matched his long game.

No-one improves in this department having been so long on the Tour. He admitted that before the B&H began and now he must solve the problem if he is to secure the major that has eluded him so far.

''That was the worst I have ever putted while in contention and I have been in contention many times over the past 10 years,'' sighed Montgomerie, who tied fifth with South African Retief Goosen. ''That is the worst I can remember.

''The longest putt I made on the front nine was a tap-in and when Darren saw my confidence go on the greens his rose.

''My longest putt of the day was on the last green (from 5ft) I scored the maximum every day instead of the minimum. All credit to him.

''He hit the ball solidly, deserved to win and I am delighted for him.''

The long-hitting Spaniard, Santiago Luna, equalled Clarke's 67 to finish three shots adrift in second place. He might even have snatched victory but could not handle the capricious breeze.

He was able to prise out six birdies and an eagle but his charge was offset by three bogeys around the turn which undermined his challenge. ''I am making progress but am still not a good player in the wind,'' he admitted.

''However, I don't want to be good all the time - I don't want to be crazy.''

Countryman Jose Maria Olazabal left in a state of despair about his driving to seek the advice of veteran guru, John Jacobs, despite displacing Ernie Els at the top of the order of merit.

His 68 and a total of 280, which took him nearer his ambition to be Europe's No.1, seemed a satisfactory performance but he was far from pleased.

''Ashamed'' was his description of his attempts off the tee.

''That is how I feel about the way I drove the ball,'' he confessed. ''It cannot get any worse, I'm hitting it both ways, left and right. After the third hole I never hit a fairway and something must be done about it now.''

The Dane, Thomas Bjorn, who also shot 67, and Florioli, tied third at 11 under par.

Aberdonians Paul Lawrie and Scott Henderson picked up their biggest pay-cheques of the season. However, both could have done better.

Lawrie closed with a 71 for a 280 total to ensure his third successive top 20 finish. Yet he could have ended top Scot if his putting had been half decent.

Rookie-of-the-year Henderson was three shots further back after bogeying the sixteenth and seventeenth. Yet he derived satisfaction from the swing-change which held up under pressure and provided accuracy off the tee.