The Sensex surged up by a whopping 244 points, or 1.47 per cent, in the opening trade today on capital inflows by foreign funds, driven primarily by a rally on global bourses. The 30-share index, which had gained 175 points in the previous session on Friday, rose by 244 points to 16,673 points with metals, auto and oil and gas sectors leading the rally. The wide-based National Stock Exchange index Nifty also went up by 74 points, or 1.26 per cent to 4,996 points, inching towards the psychological 5,000-points level. Stock brokers said trading sentiments were helped by an overnight gain in the US markets and cut in surcharge on corporate tax in the Budget, triggering widespread buying.