The JSE's benchmark Top-40 index rose 1.9 percent to 43,682 points, while the broader All-share index gained 1.9 percent to 50,322 points.
By 1500 GMT the rand gained 0.4 percent to 13.8575 per dollar, its firmest since Dec. 12.
Despite a broadly firmer dollar, gold prices remained near two-week highs while copper was nearly 1 percent higher, further indications of robust commodity demand going into 2017.
Mining firms BHP Billiton, Anglo American and Anglogold Ashanti all rallied more than 2 percent, lifting the bourse to a near two-week high. Sappi was the biggest gainer among the blue chips, advancing 4.4 percent to close on 89.50 rand.
Bonds were also firmer, with the yield on the benchmark government paper due in 2026 dropping 1 basis point to 8.97 percent..