The Sensex at the Bombay Stock Exchange closed with a good gain of 177 points, or 1 percent, at 17,727, on value buying in blue-chips on Thursday. The Nifty at the National Stock Exchange rose 42 points, or 0.8 percent, to 5,320. Stock markets in Japan, China, Hong Kong, South Korea and Singapore ended mixed, after the US central bank lowered its growth forecast for the world's biggest economy, fueling global growth concerns.