Major sell-off in global financial markets on renewed concerns about the eurozone's debt crisis sparked a broad-based unwinding in domestic bourses as the benchmark CNX Nifty tanked by 100 points at the National Stock Exchange (NSE) here today. Worries about form of debt restructuring by Greece was a key flash point of today's sell-off in Southeast Asian and European stock markets,which crashed to multi-week lows on concern that Greece's debt problems could hurt the recovery pace of global economy. The 50-share index touched a low of 5,373.00 before finishing at 5,386.55,a net fall of 99.80 points,or 1.82 per cent,over its last close. Market came under heavy selling in opening trade itself on the backdrop of global fallout and ahead of expiry week,and continued to slide as trading progressed. It made a brief attempt to recover but crumbled under the selling spree. Frenzied selling in heavyweights across the sectors put immense pressure on the key index,which finally closed below the psychological 5,400 mark. However,FMCG space managed to withstand the storm. BHEL,Sesa Goa,IDFC,Reliance Infra,Tata Motors,Tata Steel,ICICI Bank,Sterlite Industries,SBIN and Axis Bank were the top losers from the Nifty pack. Bucking the negative trend,GAIL,ITC,Ambuja Cement and Siemens managed to end with good gains. Total turnover in cash segment dropped to Rs 9,248.55 crore from Rs 10,184.84 crore on Friday. A total of 4,679.14 lakh shares changed hands in 49,50,276 trades. The market capitalisation was at Rs 63,35,055 crore.