Twenty-time Grand slam winner, Roger Federer became the oldest world number one after he defeated his Dutch opponent Robin Haase in Rotterdam at the ABN Amro World Tennis Tournament. The Swiss champion once again claimed the top spot after dispatching Haase 4-6, 6-1, 6-1 in the quarterfinals in Rotterdam. In the semi-finals, he would be playing against the winner from the Andreas Seppi and Daniil Medvedev quarterfinal match.