Nystrom shot a 7-under-par 65 in the morning and Owen shot his 65 in the afternoon. Owen birdied eight holes in a 10-hole stretch to move to 8-under, but his bogey at the 18th dropped him back into a tie with the Swede Nystrom.
The pair are one stroke ahead of two at 66, Ricardo Gonzales and John Senden.
Owen, an Englishman who stands 6-foot-3, admitted that the British Open took its toll. It was an incredible experience and one I am never going to forget, he said. It took me nearly a month to come down, but I gave myself a good talking-to after missing the cut at the Gleneagles Scottish PGA Championship, and my puttings come good again.
Owen is 39th in the Order of Merit, Europes money list. Nystrom is in 121st position and must worry about maintaining his card.
I changed my putting at the BMW International Open, and my form has gradually come back, said Nystrom.
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