GALLE, July 29 (Reuters) India beat Sri Lanka by 304 runs on the fourth day of the first test today to take a 1-0 lead in the three-test series. The hosts, chasing a mammoth 550 for a win, only managed 245 runs before their second innings folded in the final session of the penultimate day after Dimuth Karunaratne had been dismissed for 97. Asela Gunaratne, who had fractured his thumb and was ruled out of the series, and stand-in captain Rangana Herath, who suffered a hand injury yesterday, did not bat for Sri Lanka in the second innings. The second test will be played from Thursday in Colombo. REUTERS KU 1637