The 30-share index flared up by 141.57 points, or 0.50 percent, to hit a new peak of 28,001.95, surpassing previous intra-day record of 27,969.82 reached on Monday.
The gauge had shed 5.45 points in the previous session. Markets remained closed on Tuesday on account of "Muharram".
All the sectoral indices, led by realty, consumer durables and power, were trading in positive zone with gains up to 1.50 percent.
Breaching all previous records, the 50-share NSE Nifty gained 39.50 points, or 0.47 percent, to hit a new lifetime high of 8,363.65. It had touched the intra-day lifetime high of 8,350.60 on Monday.
Marketmen said persistent inflow of foreign funds and sustained buying by retail investors, buoyed by a series of economic reforms undertaken by the government and better-than-expected earnings by blue-chip companies, lifted the key indices to new highs.
Prominent gainers among the 30 Sensex stocks were Bajaj Auto, BHEL, Cipla, ITC, L&T, SBI, Sun Pharma, TCS, Tata Motors and Tata Power.
Among other Asian markets, Japan's Nikkei fell 0.21 percent, while Hong Kong's Hang Seng shed 0.62 percent in morning trade on Wednesday
US Dow Jones Industrial Average closed 0.10 percent higher in Tuesday's trade.