Electing to bat, the Indian batsmen put on board a decent 278 for six with Devdutt Padikkal (71), skipper Aryan Juyal (60) and Yash Rathod (56) scoring half-centuries.
After early fall of Atharwa Taide (20), Padikkal and Pawan Shah (36) added 74 runs for the second wicket before Sandun Mendis broke the stand by scalping the latter.
The following batsmen used the platform to post the highest score of the series. India then bowled out the hosts for 143 in 37.2 overs with off-spinner Badoni taking three wickets for just 35 runs and left-arm spinner Tyagi also accounting for three Sri Lankan batsmen.
Opener Navod Paranavithana top scored for the hosts with his 45-run knock while captain Nipun Dananjaya Perera contributed 36.
The decisive fifth ODI will be played on Thursday at the same venue.
India Under 19: 278 for 6 in 50 overs. (D Padikkal 71, A Juyal 60; S Mendis 2/37, S Lakshan 2/48)
Sri Lanka Under 19: 143 all out in 37.2 overs. (N Paranavithana 45; A Badoni 3/35, H Tyagi 3/37).
First Published: August 7, 2018, 11:10 PM IST