The BSE benchmark Sensex rose by over 51 points in early trade today on sustained buying by funds and retailers amid a firm global trend. The 30-share barometer, which had gained 33.07 points in yesterday's trade, moved up further by 51.50 points, or 0.28 per cent, to 18,662.27. Stocks of auto, consumer durables and banking sector led the rise. Similarly, the wide-based National Stock Exchange index Nifty gained 14.35 points, or 0.25 per cent, to 5,674.60.