Kenya captain Steve Tikolo described Collins Obuya's bowling as the "spell of his life" after his five-wicket haul steered his side to a surprise win over Sri Lanka.
Otieno smashed 60 runs off 88 balls
Obuya ended with figures of five for 24, the ninth best bowling figures in World Cup history.
And he picked up the man-of-the-match award for his efforts, which reduced the Sri Lankans to a 53-run defeat.
Afterwards Tikolo said: "Collins Obuya bowled the spell of his life to win the game for us."
Kenya had set the Sri Lankans 211 for victory in front of their home crowd in Nairobi.
Kennedy Otieno starred with the bat and took two catches behind the stumps, much to the delight of Tikolo.
The Kenyan skipper added: "We told Otieno he would come good and he did.
"That said, I thought we were 30 to 40 runs shot in our batting but we bowled superbly to finish them off."
Maybe we can go to the Super Six stage
Man of the match Collins Obuya
Kenya now have 12 points in Group B following wins over Canada and Sri Lanka, and after being gifted four points when New Zealand pulled out of their game against the Kenyans in Nairobi.
But despite seeing his team top the group, Tikolo refused to get carried away with their chances of qualifying for the Super Six stage.
He added: "We don't want to take anything lightly. We still have to work hard for the next two games."
Collins Obuya, however, was more confident about the team's chances for the rest of the tournament.
He said: "We are looking forward to playing Bangladesh and maybe we can go to the Super Six stage."
Kenya face Bangladesh on Saturday, with their final group game against the West Indies on Tuesday.