The BSE benchmark index, which had gained 455 points in the last four trading sessions, opened a tad higher from yesterday's level on flat global cues.
With momentum picking speed in the last two hours, Sensex finally closed 86.17 points, or 0.49 per cent, up at 17,852.95 -- its highest level since August 21.
The 30-share index was led by gains in HDFC, NTPC, GAIL, TCS and ICICI Bank that gained in 1.2-2.5 per cent range.
Brokers said trading sentiment remained better for the fifth day on hopes of a repo rate cut by RBI in its upcoming meeting.
The pressure on RBI to cut interest rates may intensify if IIP data slated for tomorrow comes out weaker-than-expected, they added.
Meanwhile, a meeting of the Cabinet Committee on Political Affairs (CCPA), which could have decided on raising diesel and cooking fuel prices, was today postponed even as Oil Minister S Jaipal Reddy said the price increase was "unavoidable".
Traders said a firming trend in Asia and higher opening in Europe further supported the uptrend in Sensex.
Metal stocks, however, buckled under pressure with reports of slowing demand. Jindal Steel, Sterlite Industries and Tata Steel were among the biggest losers in Sensex.
The broad-based National Stock Exchange swung between gains and losses before ending higher by 26.55 points, or 0.50 per cent to 5,390.
