In the semi-finals, Federer will face Karen Khachanov, who won the battle of the young Russians against Andrey Rublev 7-6 (10/8) 4-6 6-3.
Federer described his Halle Open final opponent as a tough player to play against and described his serve as wonderful and his backhand as one of the best in the game.
In Halle this week, Roger Federer analyzed the current situation his main rivals are going through and their recent results.
This is set to be a really interesting match as it is between two players are at two very different stages of their career.
Conservatives on Capitol Hill anxiously await health care bill
The bill will be brought to the Senate floor once the CBO has assessed its cost and impact, "likely next week", McConnell said. But Republicans from states that expanded Medicaid, like Ohio's Rob Portman, want to extend that to seven years.
Federer wrapped up the opening set after the first three games went against serve and there was a break apiece in the second before the legendary Swiss fended off a couple of set points to force a tie-break.
The 35-year-old victor claimed the Halle Open title one week ahead of the Wimbledon tournament, the third Grand Slam of the season, which he has won seven times. He improved his Halle record to 57-6. But Kvitova stepped up her game at the start of the second, breaking for 2-0 and moving to the brink of levelling the match when she secured a double break to move 5-1 in front.
"I thought it was extremely close, especially that second set".
Fourth-seeded Alexander Zverev of Germany knocked off No. 7 seed Roberto Bautista Agut of Spain 6-7 (6), 7-6 (1), 6-1 to advance in another quarterfinal match.
Petra Kvitova secured the best win of her comeback so far, beating Kristina Mladenovic to reach the semi-finals of the Aegon Classic in Birmingham.
Federer, who hit 11 aces and 32 winners, said facing Khachanov, who he has never played previously - at least competitively, will present a new challenge for him.