Equity benchmark NSE Nifty touched the psychological mark of 10,000 for the first time in Tuesday's opening trade. The broader index opened at 10,010.55, gaining 44.15 points.The 30-share BSE Sensex was also on a surge as it opened at 32,350.71, up by 104.84 points. Sensex was up by 0.12 per cent while Nifty was gaining more than 0.20 per cent.However, soon after opening, the Nifty slipped below the landmark, making the affair a touch-and-go one.At 10.33 AM, Nifty was trading flattish at 9,969.65 while Sensex was moderately in the green at 32,260.73.Analysts believe that the continuous rally of global markets coupled with influx of foreign investments have kept the bull run going in stock markets. In spite of the global markets closing on a mixed note on Friday, the Indian stock markets have managed to guard against market correction in the first two days of the week.Experts are of the opinion that Nifty needs to cross the mark of 10,020-25, to be able to hold on to the gains.Impressive quarterly showings by Reliance Industries on Friday and HDFC Bank on Monday have boosted investor sentiments.Hero MotoCorp, Tata Steel and Bharti Airtel were the major gainers while Lupin, Cipla, ONGC, Wipro and HCL Tech were losing the most. Watch Nifty breaches the 10,000-mark for first time ever