Defending under-15 champions Comras must overcome stiff competition from hosts Nakuru RFC in order to retain the title as the Great Rift Championships gets underway this morning at Menengai High School. The two teams are in Pool B with Impala RFC, Shamas A and Sure 24 in the cut throat competition for the two semi-final slots. In Pool A are New Life, Menengai High School, Nakuru Day Secondary School, Shamas B and Western RFC.