Top-seeded Daniil Medvedev delivered 10 aces while posting a 7-6 (4), 6-3 victory over Ilya Ivashka on Thursday to reach the quarterfinals of the Wortmann Open in Halle, Germany.
Medvedev of Russia had to battle to win a first-set tiebreak before cruising through the second set. He saved all six break points while Ivashka of Belarus saved five of six.
Medvedev next faces seventh-seeded Roberto Bautista Agut after the Spaniard posted a 6-7 (6), 6-4, 6-2 victory over Netherlands qualifier Tallon Griekspoor. Bautista Agut racked up 16 aces.
Eighth-seeded Russian Karen Khachanov beat Serbia's Laslo Djere 7-6 (4), 6-4. His quarterfinal opponent will be German Oscar Otte, who rallied for a 4-6, 6-0, 7-6 (3) triumph over Nikoloz Basilashvili of Georgia.
Second-seeded Matteo Berrettini smoked 22 aces while rallying for a 3-6, 7-6 (5), 6-4 victory over lucky loser Denis Kudla to reach the quarterfinals in London.
The Italian was outplayed in the first set and then delivered nine aces in each of the final two sets to subdue Kudla. Berrettini saved seven of nine break points while Kudla saved five of seven.
Berrettini will next play Tommy Paul, who rolled to a 6-1, 6-4 victory over Stan Wawrinka of Switzerland. Paul converted 74.3 percent of his first-serve points and won the match in 65 minutes.
Serbia's Filip Krajinovic recorded a 4-6, 6-3, 6-4 win over qualifier Sam Querrey. Krajinovic will next face Brit wild card Ryan Peniston, who outlasted Argentina's Francisco Cerundolo 6-0, 4-6, 6-4.
--Field Level Media