Equity benchmark Sensex plummeted over 800 points in early trade on Friday, on heavy across-the-board selling amid a negative trend in global markets and unabated foreign fund outflows.

The 30-share index was trading 810.29 points or 1.38 per cent lower at 57,984.80. Similarly, the Nifty plunged 245.15 points or 1.40 per cent to 17,291.10.

Maruti was the top loser in the Sensex pack, shedding nearly 3 per cent, followed by Bajaj Finserv, Kotak Bank, HDFC, Bajaj Finance and Tata Steel.

On the other hand, Dr Reddy's and Sun Pharma were the gainers.

In the previous session, Sensex ended 454.10 points or 0.78 per cent higher at 58,795.09, and Nifty surged 121.20 points or 0.70 per cent to close at 17,536.25.

Foreign institutional investors (FIIs) were net sellers in the capital market, as they offloaded shares worth Rs 2,300.65 crore on Thursday, as per exchange data.

According to VK Vijayakumar, Chief investment Strategist at Geojit Financial Services, when a stock which has more than 10 per cent weight in Nifty surges by 6 per cent, it will trigger a strong upmove in the index. This happened on Thursday, when the spurt in RIL moved the Nifty up by 121 points.

"But this uptrend is unlikely to sustain and can easily reverse when the headwinds for the market turn stronger," he said.

He noted that the new headwind is the latest variant of the virus detected in South Africa, Botswana and Hong Kong. "This along with sustained selling by FIIs for the seventh consecutive day are major sentiment negatives for the market," he said.

Elsewhere in Asia, bourses in Shanghai, Hong Kong, Seoul and Tokyo fell up to 2.68 per cent in mid-session deals.

Stock exchanges in the US ended largely positive in the overnight session.

Meanwhile, international oil benchmark Brent crude fell 2.02 per cent to USD 80.56 per barrel.