Widmark's 10-under-par 134 is one stroke clear of fellow Swede Mikael Lundberg, who stands alone in second place after a round of 4-under 68. Ben Mason (68) and Shaun P. Webster (68) of England share third place at 8- under 136, while Spain's Jesus Maria Arruti (70) is alone in fifth place at minus-7.
Scotland's Marc Warren fired the tournament's low score with an 8-under 64 and leads a group of four knotted in sixth place at 6-under-par 138.
This tournament is the third dual-ranking event of the 2005 season for the European and Challenge Tours. And with the PGA Championship being played eight time zones away, no player ranked in the Order of Merit's top-100 is in the field.
Eighty-five golfers missed the cut, which was set at even-par, and 70 moved on to play the weekend.
Widmark, who is sixth in the Challenge Tour rankings after a pair of titles this year, opened his round on the back nine and promptly moved to 7 under with birdies at the par-4 10th and the par-3 11th. He dropped a shot at No. 15, but made the turn at minus-8 after consecutive birdies at 17 and 18.
'I got off to a good start today with birdies at the 10th and 11th and things went on nicely,' said Widmark.
A par at No. 1 was followed by three straight birdies as Widmark moved to 11 under. The 29-year-old then found himself face-to-face with two holes that gave him trouble on Thursday: the 576-yard, par-5 fifth, which he bogeyed in the first round, and the par-4 sixth, where he dropped two strokes with a double-bogey Thursday.
Widmark collected par at both holes, but then dropped a shot with a bogey at No. 8 to fall to minus-10.
'I had a poor finish...by hitting bad approach shots into the last four holes, which made me make bogey on the eighth,' said Widmark. 'But all in all, a very good day.
'I do feel confident at the moment and I am enjoying the game. If you play good golf then it is all the more enjoyable. There's nothing worse than to be on the golf course and you are playing badly and things don't happen -- that is the worst feeling. But if you do play well like I am now then there is no better feeling, so I am excited.'
Scotland's Sebastien Delagrange and Johan Edfors of Sweden both shot 5- under 67s in their second round to lead a group of eight golfers tied for 10th place at 5-under-par 139. Two-time Russian Open champion Iain Pyman of England is among the eight after an even-par 72 Friday.
Overnight leader Tom Whitehouse of England stumbled to a 3-over 75 to fall into a tie for 26th at 3-under-par 141.