Opener Shikhar Dhawan's blazing century and a disciplined effort by India's spinners have powered them to a nine-wicket win over Sri Lanka in the first one-day international.
Chasing a modest 217 for victory, India rode on an unbeaten 197-run stand between Dhawan, who smashed 132 not out, and skipper Virat Kohli, who made 82 not out, to canter home in 28.5 overs.
The left-handed Dhawan hit the winning runs with a boundary and later received the man of the match award for his 90-ball blitz.
But it was the spinners, led by Axar Patel, who set up the opening win for the visitors in the five-match series after helping to bowl out Sri Lanka for 216 in 43.2 overs.
India, who last week achieved their first clean sweep in an overseas three-Test series, lost an early wicket after Rohit Sharma was run out for four.
The partnership between Dhawan, who hit his 11th ODI century, and Kohli made sure India had no more hiccups in their road to victory.
"We really enjoyed batting together, me and Shikhar ... the good thing is that he is cashing in on his good form," Kohli said of his swashbuckling opener.
"He is in a good state of mind and we make sure we do everything to keep him in that zone because he is a match winner.
"When he plays like that he will win you games of cricket and that's why we back him so much."
Dhawan was in marauding form, hitting 20 fours and 3 sixes, but Kohli also attacked the opposition during his 70-ball stay at the crease.
New limited-overs captain Upul Tharanga rotated his bowling options at Rangiri Dambulla International Stadium but failed to stop the onslaught.
It was a forgettable 200th ODI for veteran paceman Lasith Malinga, who was not only stuck on 298 wickets but was carted for 52 runs in his eight overs.
Earlier put into bat, opener Niroshan Dickwella's 74-ball 64 took Sri Lanka to 1-139 in the 25th over before their batting imploded.
Patel claimed three wickets with his left-arm spin to return career-best figures of 3-34. Fellow spinners Yuzvendra Chahal, Kedar Jadhav and paceman Jasprit Bumrah took two wickets each.
"At 139-1 we surely had a bit to think about but again the way the bowler came back into the game and got us those breakthroughs along with our fielding really made the difference," said Kohli.
Former captain Angelo Mathews tried to stick around with the lower-order but eventually ran out of partners to be stranded on 36.
"We started really well and after that we didn't capitalise. The middle order collapsed. One stage, we were thinking of 300," said a disappointed Tharanga.
"If you want to score 300 in an ODI, someone has to get a big score and that is what we are lacking in the last one or two years. We have to learn from the mistakes," he added.
Sri Lanka must win at least two games in the series to gain direct entry into the 2019 World Cup.
The second ODI is scheduled for Thursday in Pallekele.
Sri Lanka: Upul Tharanga (c), Angelo Mathews, Niroshan Dickwella (wk), Dhanushka Gunathilaka, Kusal Mendis, Chamara Kapugedara, Lakshan Sandakan, Thisara Perera, Wanindu Hasaranga, Lasith Malinga, Vishwa Fernando.
India: Virat Kohli (c), Shikhar Dhawan, Rohit Sharma, Lokesh Rahul, Kedar Jadhav, Mahendra Singh Dhoni (wk), Hardik Pandya, Axar Patel, Yuzvendra Chahal, Jasprit Bumrah, Bhuvneshwar Kumar.