JOHANNESBURG (Reuters) - South Africa's rand raced to a two-week high against the dollar on Friday as the greenback came under pressure after a report that investigators probing possible Russian interference in the U.S. election had subpoenaed President Donald Trump's election campaign for documents. Bourse heavyweight Naspers helped push South African stocks higher. At 1511 GMT, the rand was trading at 14.0450 per dollar, 0.8 percent firmer than its close on Thursday. The currency had touched a session high of 13.9575, its firmest since Nov. 2. "Basically the dollar weakness is making us look good," said currency strategist at IG Markets Shaun Murison. "The dollar has been on the back foot following the re-emergence of concerns relating to Russia’s involvement in U.S. elections." However, investors in South African assets remained nervous ahead of credit ratings reviews on Nov. 24. "With investor jitters rising ahead of South Africa rating review by S&P Global and Moody’s agencies next week, further downside could be on the cards," Lukman Otunuga, research analyst at FXTM, said in a note. A one-notch downgrade of the local-currency rating by both agencies could trigger forced selling of up to $12 billion of the country's bonds, as well as triggering a heavy selloff the rand. Yields on government bonds were lower, with the benchmark 10-year paper due in 2026 down 2 basis points to 9.34 percent. On the stock market, the Top-40 index was up 0.99 percent to 53,909.14, while the broader all-share rose 0.97 percent to 60,128.41. Naspers, which holds a 33 percent stake in Hong Kong listed Tencent, rose 3.5 percent to 3845.00 rand buoyed by gains in the Chinese gaming giant. (Reporting by Olivia Kumwenda-Mtambo; Editing by Gareth Jones)