Swashbuckling opener Virender Sehwag bludgeoned the Sri Lankan bowling with an unbeaten 284-run knock to guide India to 443 for one in reply to Sri Lanka's first innings score of 393 all out on the second day of the third and final Cricket Test at Mumbai on Thursday.India now have a lead of 50 runs with nine first innings wickets still in hand and three days of play left.Sehwag scored the second fastest double century off just 168 deliveries, inclusive of 27 boundaries and six sixes.His 221-run opening stand with Murali Vijay, who made 87 and another marathon partnership with Rahul Dravid 62 not out put India in complete control.Sehwag also became the third highest scorer in a single day behind Don Bradman 309 and Wally Hammond 295.Sehwag on Thursday became the third fastest Indian to score 6000 Test runs after Sachin Tendulkar and Sunil Gavaskar. Sehwag, who needed 45 runs going into today's match to reach 6000, took 123 innings to reach the milestone while Tendulkar and Gavaskar did the same in 120 and 117 innings.Sehwag also became the eighth Indian to cross the 6000-run mark in Test cricket. Playing in his 72nd Test, he has now 6213 runs with 17 hundreds and 19 half-centuries at an average of 52.65.India, who are leading the series 1-0, will leapfrog to the top of the ICC Test rankings if they win this match, which will be the first time that they will occupy the top slot.Earlier, resuming at the overnight score of 366 for eight, Sri Lanka were all out for 393. Angelo Mathews missed his maiden hundred by one run.For India, Harbhajan Singh took four wickets, Pragyan Ojha three and Zaheer Khan and S.Sreesanth one each.