The 50-issue Nifty regained the psychological 7,800-level for the first time since July 25 by surging 56.60 points, or 0.72 per cent, to trade at an all-time high of 7,848.30, surpassing its previous intra-day high of 7,840.95 touched on July 25.
Similarly, the benchmark BSE Sensex also climbed 217.43 points, or 0.83 per cent, to trade at 26,320.66, breaching its earlier high of 26,300.17 (intra-day) reached on July 25.
The gauge had rallied over 774 points in previous four sessions.
In NSE-50 constituents, 41 stocks led by banking, oil & gas and power were trading in positive zone.
Brokers said market sentiments were upbeat on sustained capital inflows and widespread buying by retail investors after several blue-chip companies posted better-than-expected first quarter earnings.
Besides, rebound in the rupee against the dollar on Friday and easing global crude oil prices buoyed trading sentiments, they said.
Major gainers which supported the Nifty to scale new life-time high were ICICI Bank, Axis Bank, SBI, HDFC Bank, BPCL, Tata Power, BHEL, Tata Motors, Larsen and Toubro and ONGC.
Further, a mixed trend at other Asian bourses and a higher opening in European markets lifted the trading sentiments here, they added.
Meanwhile, Foreign Portfolio Investors (FPIs) bought shares worth a net Rs 625.18 crore in the previous session, as per provisional data from the stock exchanges.
Among other Asian markets, Hong Kong's Hang Seng was down 0.15 per cent while Japan's Nikkei rose 0.23 per cent in early trade today.