After Thursday's play was washed out completely, the second round was contested on Saturday.
The final 36 holes will be played on Sunday. The cut was 50 players and ties, instead of the normal 70 and ties so that 36 holes can be played on Sunday. A total of 54 players will play the final round.
Bradley Dredge carded a 3-under 69 and stands alone in second place at 9-under-par 135. U.S. Open champion Michael Campbell, who shared the lead after one round with Henrik Stenson, shot a 1-under 71. He was joined at minus-8 by Peter Lawrie.
Stenson and Mark Roe were one stroke further back at 7-under-par 137.
Fasth got his round going with a birdie on the par-5 third. He came back with a birdie on the sixth at Gut Kaden Golf and Land Club to get to minus-6.
The Swede faltered to a bogey on the eighth. After three straight pars, Fasth rolled in consecutive birdie putts from the 12th. The two-time winner on the European Tour birdied the 15th for the second straight round to climb to minus-8.
Fasth made it two in a row as his birdie putt on 16 dropped into the cup. The 33-year-old closed with a birdie at the last to take the outright lead for the first time.
'I played fantastic on the front nine and just didn't get the score going,' Fasth said. 'I hit it really close on the 10th and 11th and missed those and I could easily have lost it there, but I stuck in because I was playing so well. Then it was a really nice finish.'
Dredge also started his round with a birdie on the third and then reeled off eight consecutive pars from there. The Welshman moved to 8 under with a birdie on the par-4 12th.
The 32-year-old tripped to the only bogey of his round at the 13th. Dredge got that shot back with a birdie on No. 15 and took second place by himself with a birdie on the par-5 17th.
'It was a steady round, a lot of fairways and greens,' said Dredge. 'I didn't have as many chances as the previous day, but I am pleased with the round.'
John Daly, the 1995 British Open champion, fired an 8-under 64 to climb to 6-under-par 138. He was joined there by Alessandro Tadini, K.J. Choi, Brian Davis, Anders Hansen, Steven O'Hara and Marcel Siem.
The cut fell at minus-2 with 54 players moving on to play the final two rounds. Trevor Immelman, the 2004 champion, missed out on the final two rounds after posting rounds of 71-75 to miss the cut by three shots.