Alexander Bjork of Sweden and Scott Jamieson of Scotland shared the halfway lead on 10 under par at the Tshwane Open as a thunderstorm disrupted the second round at Pretoria County Club on Friday. Tour rookie Bjork, who was in a three-way tie for the lead after the first round, kept up his form with a four-under-par 67 which included two bogeys. “I had some troubles on some holes with the distance on the irons but overall it was a good round.” Jamieson added a 65, including seven birdies and a bogey, to his opening 67 for a two-round total of 132.