Tharanga, though missed his century, went for 12 fours and 3 sixes, frustrating the Indian bowlers.
Kuldeep Yadav replaces Washington Sundar in the Indian side.
When India came to bat, they lost Rohit Sharma for only 7 and this was a great start for Sri Lanka.
Sadeera Samarawickrama gave a good company to Thranga at the crease as the due stitched together a 121-run partnership for the second wicket, after Danushka Gunathilaka (13 off 12, 2 fours) departed early.
Captain Thisara Perera, meanwhile, had an innings to forget as he got out for just six runs.
At one stage, Sri Lanka were reigning at 160/3 but quickly lost the next seven wickets for just 54 runs, fading the efforts put by Tharanga and Samarawickrama, who scored 95 and 42 respectively.
Angelo Mathews also failed to perform this time as he was cleaned up by a ripper from Chahal.
Shikhar Dhawan scored a brilliant hundred to cruise India to the series winning eight-wicket victory over Sri Lanka in the third and final One Day International at the YS Rajasekhara Reddy stadium here on Sunday. The frontline pairing of Bhuvneshwar Kumar and Jasprit Bumrah were repeatedly picked for boundaries by Tharanga.
In the series against South Africa, he smashed 119 in Cape Town and averaged 37.8 in the series.
After Rohit won the toss and opted to field fearing the evening dew would make it hard for his spinners to grip the ball, Sri Lanka lost opener Danushka Gunathilaka for 13. In 2017, the Lankans have won five out of 27 ODIs, and will look to sign off woith a win.
Washington Sundar, too, picked up his first global wicket on Wednesday, when he bowled out Lahiru Thirimanne on Wednesday.
Rohit Sharma's astute captaincy skills in the IPL has helped him lift three trophies.
An unbeaten 111 and was economical with the ball, finishing with a spell of 0-9 from 4 overs, at an economy rate of 2.25. Yuzvendra Chahal and Kuldeep shared 6 wickets together, three each, to break the momentum of the visitors who were looking string at 136/1 in 22.2 overs. Nuwan Pradeep, who was taken for 106 in 10 overs, will look for redemption if he retains his place in the XI while Suranga Lakmal holds the key for Sri Lanka.
The match is scheduled to start at 1.30 pm IST.
The match can be seen live on Star Sports 1 and Star Sports 1HD.