Maintaining its rising streak for the fifth session in a row, the benchmark Sensex rose by 82 points in opening trade on Tuesday on heavy buying by foreign funds amid expectations of strong corporate earnings. The 30-share index, Sensex, moved up by 82.40 points, or 0.45 per cent, to 16,823.70, with shares of auto, oil and gas, metal and healthcare sectors leading the rally.The Bombay Stock Exchange barometer had gained over 527 points in the past four sessions. The wide-based National Stock Exchange index Nifty shot up by 23.55 points, or 0.42 per cent, to 4,999.60.Brokers said continued buying by foreign funds and retail investors in heavy-weight stocks on expectations of strong corporate earnings in the second quarter mainly influenced the trading sentiment. Auto sector index rose by 1.02 per cent at 6,670.18 on the back of improving demand for vehicles. Maruti Suzuki gained 1.27 per cent at Rs 1,661.70, Mahindra and Mahindra 0.52 per cent at Rs 889.60, Tata Motors 0.84 per cent at Rs 604 and Hero Honda 2.35 per cent to Rs 1,718.Besides, Reliance Industries gained 1.35 per cent to Rs 2,127, Reliance Infra 0.71 per cent to Rs 1,252, DLF Ltd 0.88 per cent to Rs 431.55 and Hindalco 1.20 per cent to Rs 139.35.The Hong Kong's Hang Seng index was up by 0.40 per cent in the morning trade on Tuesday, while the Japan Stock Exchange was closed.