FIRST ROUND LEADERBOARD: (GB & Ire unless stated)
-6 S Kjeldsen (Den) -3 S Garcia (Spa) -2 A Wall, D Lynn -1 H Otto (SAF), L Westwood Selected others: +2 C Montgomerie, R Karlsson, MA Jimenez +5 I Poulter, P Harrington +9 J Rose
Padraig Harrington (left) is chasing Robert Karlsson for the Order of Merit
Robert Karlsson made a steady start as his main Order of Merit rival Padraig Harrington struggled on the first day of the Volvo Masters at Valderrama.
The Swede, who needs to finish ahead of Harrington, Lee Westwood and Miguel Angel Jimenez to become Europe's new number one, shot a two-over-par 73.
That left the 39-year-old three ahead of Harrington, on the same score as Jimenez but three behind Westwood.
Denmark's Soren Kjeldsen shot a six- under 65 to take the tournament lead.
Sergio Garcia finished with a 68 to sit second on a windy day in his home country Spain.
English pair Anthony Wall and David Lynn trailed Kjeldsen by four strokes in third ahead of Hennie Otto (70) of South Africa and Westwood.
Ryder Cup star Karlsson struggled for form with his putter initially but he rallied late on and was pleased with his final score on day one.
"I can't do much more. At the end of the day I shot 73 and it was a great day to walk away with 73," said Karlsson.
"The greens were so quick that if you just missed a few then you could also lose your confidence."
Three-time major winner Harrington could clinch the Order of Merit with a victory coupled by a Karlsson fourth or worse finish, or a runner-up placing with Karlsson sixth or worse.
"All my good shots were flying long. It was difficult out there," said Harrington, who reached only two of the first nine greens in regulation.
Westwood needs a victory coupled with Karlsson finishing no higher than fourth to earn his first Merit title since 2000.
The Englishman added: "There's only one time worth looking at the leaderboard and that's with nine holes left to play on Sunday when everything sorts itself out."
Spanish star Jimenez is £523,968 behind Karlsson, so he would have to win and hope that Karlsson, hoping to become the first Swede to win the Order of Merit title, finishes outside the top 20.
But Jimenez could only match Karlsson's score with a 73, harming hopes of a maiden title for the 44-year-old.
Other issues at stake include finalising the top 15 players on the Order of Merit who will secure a place in next year's US Open at Bethpage in New York, while the top 30 also qualify for The Open at Turnberry.
Meanwhile Justin Rose, winner of the Order of Merit and Volvo Masters titles last year, continued his woeful run of form with a nine over par round of 80.
"I'm just playing poorly right now - everything is hard work."