The Swiss player will usurp his Spanish rival in the ATP rankings after beating Kyrgios in sem-finals in Germany
Roger Federer regains world No 1 spot after Nick Kyrgios win in Stuttgart Cup
Roger Federer will return to world No 1 on Monday when the new ATP rankings are published after he beat Nick Kyrgios 6-7, 6-2, 7-6 in the semi-finals of the Stuttgart Cup on Saturday.
The 20-time major winner's success means even if he loses Sunday's finals against Milos Raonic he will still gain sufficient ranking points from his run to the last four in Germany to usurp Rafael Nadal as No 1.
Federer had returned to world No 1 for the first time since 2012 in February, but he had lost the spot to Nadal in April after he had lost in the second round in Miami.
Federer had not played since then, missing the whole clay court season as he chose to rest ahead of the grass court action and his bid to win a ninth Wimbledon title in July.