The bluechip index, which had surged to 21,039.42 at the outset for the first time since November 2010, gave up gains to close down 42.45 points, or 0.20 per cent, at 20,725.43.
19 Sensex stocks declined led by Reliance Industries, Infosys, Tata Consultancy Services and Wipro. Coal India, BHEL, Bajaj Auto, Hero MotoCorp, Dr Reddy's, Jindal Steel, NTPC and Tata Steel also saw losses.
On similar lines, the 50-scrip National Stock Exchange index Nifty fell by 14 points, or 0.23 per cent, to 6,164.35, after climbing to 6,252.45. Also, SX40 index, the flagship index of MCX-SX, closed at 12,331.32, down 7.5 points.
Across the market, IT, Power and Realty shares ended the session in negative zone while Capital Goods, Auto and Consumer Durables closed in the green.
Brokers said the rally fizzled out as investors judged the rally as overdone. Also, a section of the market appeared worried after recent disappointments in earnings led by Jet Airways and Ambuja Cements and booked profits, they added.
