Edwin Kipsang Rotich (1:02:25) finished just two seconds ahead of Giovani dos Santos (1:02:27) to win the Meia Maratona Internacional do Rio de Janeiro in Brazil.
More than 11,100 runners came out for the coastline cruise.
Richard Kiplimo Mutai (1:04:55) rounded out the top three with a time of 1:04:55.
He finished seventh a year ago.
For the women, it was Nancy Jepkosgei Kiprop (1:12:37) defending her title against Delvine Relin Meringor (1:12:55) who repeated in second.
Sueli Pereira Silva (1:14:16) cut close to three minutes from her seventh-place finish in 2014 to take third.