IT has often been said that tennis is predominantly a game of the mind.

And rarely can that have been more graphically illustrated than in last weekend's XL Open final at Coral Beach.

Mental toughness was a decisive factor in the victory of Spain's Fernando Vicente in as entertaining a final as the tournament organisers could have hoped for.

Time and again, the match appeared to be heading the way of Luxembourg's Gilles Muller, but his irrepressible opponent simply refused to accept defeat.

Last year Muller twice stunned the tennis world, with shock victories over world number two Rafael Nadal at Wimbledon and over Andy Roddick in the US Open. The 22-year-old left-hander showed some of that quality as he steamrollered Vicente 6-2 in the first set.

In fact, Muller seemed to have the edge in terms of shot-making ability throughout, showing off an impressive all-court game, making more forays to the net than most dare to attempt on the green clay of Coral Beach.

But there is more to winning top-level tennis matches than playing good tennis. And it was Muller's slips of concentration at pivotal moments that let in his opponent.

In the second set, Vicente gave himself an injection of confidence by breaking Muller to love in the opening game.

The Spaniard's nagging consistency from the baseline started to draw some errors from Muller, as the winners suddenly stopped coming so easily. Simultaneously, Vicente started to pull off a few spectacular winners of his own and disrupted Muller's rhythm by throwing in a few drop shots and even venturing to the net on the odd occasion.

Vicente took the set 6-2 to force a championship-deciding third set. It lasted just shy of an hour, as long as the first two sets combined.

It looked as if Muller would be the one to bank the $14,400 winner's cheque, as he raced into a 3-0 lead, but Vicente characteristically clawed his way back to tie it up at 3-3.

Muller broke the Spaniard's serve again to forge ahead once more. At 5-3 and serving for the match at 30-15, Muller fluffed an easy smash at the net. The gasps of surprise from a packed house signalled a turning point.

Muller's state of mind can not have been helped by a controversial moment a point earlier, when Vicente angrily whacked a ball into the ground and it sailed over the fence onto the South Road verge.

Muller should have been awarded a penalty point at that critical juncture, because Vicente's tantrum was a second offence. During the second set the umpire had issued him with a violation, after the player launched a ball high into the crowd at the south end of the court in a moment of frustration.

Muller bounced back in the next game to lead 40-15 on his opponent's serve, giving himself two match points. But he just could not find a way to kill off the challenge of the Spaniard.

Vicente pulled off two breathtaking shots to deny Muller the title, the first a tremendous retrieval on the backhand side.

He followed that up with drop shot played to perfection from a deep position, an outrageously audacious way to survive a second match point. That he should even have thought of attempting it was a testament to his courage and a mentality strong enough to maintain full concentration at the most nerve-wracking moment of all.

All the drama seemed to rattle Muller to the point where his game disintegrated in the face of Vicente's never-say-die relentlessness. The 29-year-old won the decisive tiebreak 7-3 to claim the crystal trophy.

There was no time for the Vicente to savour his moment of glory. After receiving the spoils of victory in front of a crowd that showed warm appreciation for both players for a display of high-class tennis, Vicente hopped straight into a taxi and headed for the airport to fly to his next event in Barcelona.

He was on court again on Tuesday and carried on his winning streak with a 7-6, 6-4 triumph against compatriot Alex Calatrava. In the second round, he lost in straight sets to Russia's Evgeny Korolev.

In professional tennis, there is no rest for the successful.

Meanwhile Muller flew off to Casablanca to compete in the Grand Prix Hassan II, a $323,250 ATP clay-court event at Al Amal Complex. Unfortunately he lost in the first round to Alexander Waske of Germany 6-4, 7-5.