Put into bat on a seamer-friendly wicket, the Kenyan batsmen did not have an answer to the visitors' bowling as the pacemen skittled them out for a paltry 98 in 26.2 overs under an overcast Nairobi sky.
Thomas Odoyo, who acted as a stand-in captain in place of the injured Steve Tikolo, was the only Kenyan batsman to offer resistance making 43 as Singh took four wickets for 29 and Kumar chipped in with 3-29.
The 20-year-old Kumar and his opening partner Yusuf Pathan - who came in as replacements of three other players who were called to join the Indian senior team in England - repaid the selectors confidence when they wrapped up the game with India 'A' reaching the target in only 7.4 overs.
Both men finished unbeaten on 57 and 29 respectively.
India 'A' play Sri Lanka 'A' in the second one-dayer on Wednesday at the same venue.
Brief Scores: Kenya 89 all out in 26.4 overs (Thomas Odoyo 43, P. Singh 4-29, P Kumar 3-28) India A 99-0 in 7.4 overs