Knights are generally better than bishops in endgames where the pawns are all on one side of the board, but here the rook gives the knight a hard time...
1.Kg3Ke6
2.Ra3g5
Black tries to stop the White king's incursion, but it isn't easy
3.Ra5Kf7
4.Kf3Kg6
5.Ke3Nh5
6.Ra6+Kg7
7.Ke4Nf4
8.Kf3
Also possible was 8.Ra2 Kf6 9.h4 Ng6 10.h5 Nf4 11.g4 and, after a check, the king occupies the pivotal f5 square.
8...Nh5
9.Kg4Nf4
10.g3Ne2
11.Re6
The sequence 11.Rd6, 12.Rd2 and 13.Kh5 also works
11...Nd4
12.Re4Nb5
13.Kh5Nd6
14.Re7+1-0
Horvath-Sherzer (1993)