In the absence of Tiger Woods, Vijay Singh, Phil Mickelson and injured defending champion Ernie Els, the seven-time European number one must have fancied his chances of the £1m (€1.5m) first prize on offer – the biggest in golf.

But Hensby, making his debut in the event, had Nick Faldo’s former caddie Fanny Sunesson helping him and, although he had still to lead in the game, he was giving Montgomerie a hard day’s work.

The Scot lost his early grip by bogeying the 14th and 15th and when Hensby pitched to four feet on the 383-yard 16th the gap was down to one.

At the long 17th Hensby hooked two drives out of bounds and conceded the hole before three-putting the 531-yard last to lose that as well, but that was not the turning point it appeared it might be.

Montgomerie bogeyed the 19th and 21st – Hensby chipped in there – and after holing from 15 feet to stay ahead on the next he missed from eight feet at the 22nd for yet another bogey.

The pair looked to be fighting for the right to take on top seed Retief Goosen in the quarter-finals.

Goosen, winner of his last two tournaments, opened against Northumberland’s Kenneth Ferrie, outsider of the 16-man field, and after bogeying the first to go one down had a superb nine birdies in the next 18 holes.

That put him five up and the gap became six when Ferrie, who qualified for a first appearance by winning the European Open, bogeyed the short 23rd.

The fastest start of all came from Luke Donald against Bernhard Langer, the man who gave him his Ryder Cup debut last September.

Donald won four of the first six holes, and had to birdie only one of them as the 48-year-old German, who made his debut back in 1981, bogeyed the first, third and sixth.

Langer did recover and had an eight-foot chance on the 18th to be only two down. But after missing that he had further bogeys at the 19th and 20th to stand five down.

New Zealand’s US Open champion Michael Campbell led Australian Geoff Ogilvy by the same margin after 22 holes, but Ogilvy’s compatriot Steve Elkington was faring much better. He led South African Tim Clark by five with 12 to play.

Olazabal rolled in 35-foot birdie putts at the sixth and eighth to be three ahead of David Howell, but the Swindon golfer fought back to be only one down after 19 and Paul McGinley trailed Thomas Bjorn by the narrowest of margins after 22 holes.

Argentina’s Angel Cabrera, who pipped McGinley for the BMW Championship title on the course in May, was three up at lunch on South African Trevor Immelman.