India, who had beaten Nepal 2-0 in Guwahati on March 12 in first leg, were clearly the inferior side at the Dashrath Rangasala Stadium. They were put under severe pressure by the Nepalese, especially in the second half, but came out unscathed at the end.
Indian captain and goalkeeper Subrata Paul and the back four gave a brilliant display to thwart a spirited Nepalese attack on several occasions, with the upright coming to the rescue of the visiting team once.
Robin Singh put the ball into the Nepal net in the 57th minute but the referee disallowed the goal as it was clear that the Indian striker had used his hand.
On the day of the first leg in Guwahati, India had slumped to their worst ever FIFA rankings at 173rd but they are expected to gain places in next month's chart after a win and a draw over Nepal - ranked 180th - over the two legs.
Englishman Stephen Constantine thus begins his second stint as India coach on a happy note but a tough road lies ahead for him and his boys as more fancied nations of the continent await in the next rounds.
India and other five round one winners will join the 34 highest-ranked teams of the continent in the second round. The 40 nations will be drawn into eight groups of five teams and compete according to a double round robin format.
The round two qualification matches will be held between June 11 and March 29 next year. The group winners and four best runners-up (total 12 teams) of round two will advance to the final round of qualifying for 2018 World Cup (as well as 2019 Asian Cup finals as it's a joint qualification process for 2018 World Cup and 2019 Asian Cup.