The Sensex at the Bombay Stock Exchange surged 119 points, or 0.7 per cent, to 17,693 in opening trade, today, on sustained buying by funds. Remaining firm, the Sensex stood 104 points, or 0.6 percent in the green, at 17,678, a short while ago. But stock markets in Japan, Hong Kong, China, Singapore, Indonesia and South Korea were all modestly lower, as speculation heightened that Greece could default on its sovereign debt obligations.