At close, the Sensex was up 237.42 points or 0.46% at 51,597.84, and the Nifty was up 56.70 points or 0.37% at 15,350.20. About 673 shares have advanced, 2663 shares declined, and 156 shares are unchanged. HUL, HDFC, Apollo Hospitals, Asian Paints and UltraTech Cement were among the top Nifty gainers, while losers were ONGC, Tata Steel, UPL, Hindalco Industries and Coal India.