Darren Clarke may have felt his 68 was a positive opening to his weekend campaign to dislodge Lee Westwood at the top of the order of merit, but that was without reckoning with the dark horse sneaking up on the outside - Thomas Bjorn.

The 27-year-old Dane, who has already won the Heineken Classic in Australia and the Spanish Open this year, yesterday carded an eight-under-par 64, just two off the course record.

He dropped a shot at the second hole but then bounced back so well that he had nine birdies in his last 16 holes.

Next week, at the Canon European Masters in Switzerland, the Ryder Cup points table begins for the 1999 match in America but Bjorn was not worried that he might be peaking one week early.

"There are many big tournaments to come before the Ryder Cup next year," he said, "and I know that if I keep playing the way I am I shall make the team again."

At the moment, though, his sights are firmly set on the top of the order of merit. With Montgomerie suffering an uncharacteristic bout of nerves, all the talk has been about Clarke's putative coup, but fourth-placed Bjorn is just £200,000 behind Westwood and a winning £141,660 cheque this weekend would go along way to strengthening his challenge.

There's a long weekend ahead though, and, as impressive as his opening round was, he still only leads by one shot from Germans Sven Struver and Thomas Gogele scoring 65, while Russell Claydon of England is on 66.

For the other Irish it was a day of mixed fortunes. Eamonn Darcy matched Clarke to stay well in touch and Paul McGinley shot a comfortable two-under-par 70, but for Des Smyth and Raymond Burns, the day was not so easy, with Smyth on a two-over 74 and Burns posting a disastrous 81.

It was a calamitous day, too, for Colin Montgomerie. His regulation 72 leaves him eight shots behind Bjorn and struggling. He could even miss the cut, which would be his third such mishap in five tournaments.

"I'm not confident in anything I'm doing," he admitted. "I might miss the cut again and that would be the second week running. I must try and avoid that."

A grim-faced Montgomerie three-putted both the 16th and 17th holes today yesterday and those two dropped shots might prove fatal tomorrow. Last year the cut in this event was made at five under par, which means that the Scot might need to shoot 67 or better in his second round to qualify for the last two rounds.

It was an outstanding day for German players as Bernhard Langer, on his 41st birthday, shot 68 and Tobias Dier, still an amateur, shot 67.