The National Stock Exchange's Nifty surged to its highest level in a month on Friday, the best weekly performance since October. The Nifty ended 0.2 per cent up at 8,513.80, adding 2.8 per cent this week. The Sensex closed up 46.34 points, or 0.17 per cent, at 28,121.89. The index gained 2.4 per cent in the week. Both marked their best weekly performance since the week ended October 31.