Jo-Wilfried Tsonga became the latest seed to lose at the Aegon Championships, beaten in straight sets by Luxembourg's Gilles Muller.
The Frenchman, seeded fifth, lost 6-4 6-4 in the second round at Queen's.
Tsonga's exit follows defeats for Andy Murray, Stan Wawrinka and Milos Raonic - the top three seeds - on Tuesday.
Croatia's fourth seed Marin Cilic and Bulgarian sixth seed Grigor Dimitrov are the leading players left in the draw at the London tournament.
Czech seventh seed Tomas Berdych plays 18-year-old Canadian Denis Shapovalov later on Wednesday.
Muller, ranked 26th, is through to the quarter-finals for the third straight year and is now on a six-match winning run on grass.