Australian No.1 Nick Kyrgios has set himself up for a Stuttgart Open semi-final showdown with Roger Federer after a three-set victory over Feliciano Lopez.

Fourth-seeded Kyrgios, who missed the French Open with an elbow injury, received a bye in the first round and then beat Germany’s Maximilian Marterer on his first match back following a two-month absence.

And the 23-year-old continued his comeback on Friday as the world No.24 defeated Spain’s Lopez 6-4 3-6 6-3 to book his place in the last four in Germany.

Kyrgios, seeking his maiden trophy on grass – with all four of his triumphs coming on hard courts – now stands between Federer reclaiming the world No.1 ranking after the Swiss great reached the last four with a 6-4 6-4 win over Argentina’s Guido Pella.

Federer will topple Rafael Nadal from the top spot if he bypasses Kyrgios in what will be their first meeting on the lawns and reaches Sunday’s final.

Federer skipped the European clay court season to concentrate on retaining his Wimbledon title next month and his plan appears to be working as the 36-year-old was in fine form on Friday.

“I thought I protected my serve except the last couple of games, but I played free, attacking tennis, so it was good fun,” the 20-time grand slam winner said after his win over Pella.

“I have to be patient and more selective in the way I play and I adapted pretty well.”

The top seed, who has won a record eight Wimbledon titles, was largely untroubled by Pella and lost just one point on serve en route to winning the opening set. He continued his momentum to clinch the victory in 65 minutes.

Meanwhile, Canadian Milos Raonic battled to a 7-6 (7-2) 7-6 (7-1) victory against third seed Tomas Berdych, of Czech Republic, to set up a last four encounter against defending champion Lucas Pouille after the Frenchman ousted Denis Istomin of Uzbekistan 6-4 6-7 (7-5) 6-3.