Marin Cilic made it into the last eight of the Queen's grass-court tournament on Wednesday, with a 7-6 (8/6) 7-5 win over Alexander Bublik.
This event acts as a warm-up for Wimbledon where Croatia's Cilic went all the way to the final in 2017 before losing to Roger Federer in straight sets.
The 33-year-old Cilic has been in good form of late, advancing to the last four of this season's French Open before losing to Casper Ruud.
But Denis Shapovalov, a Wimbledon semi-finalist last year, was beaten in the first round at Queen's on Wednesday, the sixth seed going down in three sets to Tommy Paul of the United States.
Paul took the first set 6-4 only for Shapovalov to draw level by taking the second set 6-2.
But Paul held his nerve to win the decider 6-4.
Finnish qualifier Emil Ruusuvuori beat Britain's Jack Draper 6-2, 7-6 (7/2) to advance into the quarter-finals.
World number 56 Ruusuvuori was in fine form, hitting 29 winners while forcing nine break points.
Defending champion Matteo Berrettini and three-time Grand Slam title winner Stan Wawrinka will try to join Cilic and Ruusuvuori in the last eight when they face Denis Kudla and world number 35 Paul on Thursday.
With no points on offer at Wimbledon this summer, due to the decision by the All England Club to ban Russian and Belarussian competitors following Russia's invasion of Ukraine, the Queen's Club event is one of last opportunities for players to boost their rankings ahead of the hard-court season.