After the 30-share index, Sensex, set a record on Wednesday by crossing the 17,000 mark, Nifty also joined the rally by surging to record level by gaining 75.05 point at 5015.55 in the first five minutes of trade.
The wide-based National Stock Exchange benchmark, Nifty, took 52 days to move from 4,500-5000 level and 203 days to move from 4000-5000.
The Sensex which made its shortest 1,000 points journey from 16K to 17K in six trading sessions, failed to hold on to the early gains and closed at 16,921.39 points.
The BSE barometer on Thursday gained 237.10 point at 17,158.49 in early morning trade.
The rally in the bourses was backed by blue chip stocks such as Reliance group, Bharti Tele and capital good stocks.
Support also came in from firming global markets.
Marketmen said firming US Dow Jones Industrial index and Nasdaq and Asian stocks boosted the trading sentiment.
Hong Kong market index Hang Seng surged above the psychological 27,000-point mark in the morning trade, as Wall Street gains and fund inflows pushed the market further into record territory.