Former Masters champion Charl Schwartzel rocketed up the leaderboard as several others struggled on day two of the Tshwane Open.

World number 43 Schwartzel, who is the highest-ranked player in the field, was six-under-par through 17 holes and five-under for the tournament when play was halted at Pretoria Country Club due to dangerous conditions.

While the rest of the field was +307 combined in the second round, Schwartzel's low scoring saw him climb 36 places to solo second behind fellow South African Anthony Michael, who carded a one-under 69 today.

America's Daniel Im and another South African, Theunis Spangenberg, are joint-third on four-under, while overnight leader Justin Harding is four behind the lead with one hole to play having gone four-over through his first 17 holes before play was suspended.