Jo-Wilfried Tsonga became the latest seed to make an early exit from this year's AEGON Championships on Wednesday, the Frenchman losing in straight sets to Gilles Muller.
Tsonga, seeded fifth for the prestigious ATP 500 event at Queen's Club in west London, was well below his flamboyant best, as Luxembourg's Muller ran out a 6-4 6-4 winner in just 70 minutes.
World number 10 Tsonga follows top seed Andy Murray and second seed Stanislas Wawrinka, French Open runner up, in bowing out of the grass-court tournament, which serves as an important warm-up to Wimbledon next month.
Muller, ranked 26th in the world, broke Tsonga once in each set and did not give up his serve throughout to reach the quarter-finals in Kensington.
Grigor Dimitrov survived an early wobble to buck the trend of upsets, the sixth seed coming from a set down to beat Julien Benneteau 4-6 6-3 6-4.
Bulgarian Dimitrov gave up his serve in the first game of the match, a lapse that cost him the opening set, but the world number 11 did not falter after that, breaking his French opponent once in each of the subsequent two sets to advance to the last eight.
Tomas Berdych also avoided becoming another early casualty, but the Czech seventh seed had to fight hard to come from behind and see off Denis Shapovalov, eventually beating the Canadian teenager 7-6 (7-4) 6-7 (4-7) 7-5.
Earlier, Donald Young had the edge over Viktor Troicki in the first match of the day, the American recording a 6-3 6-4 victory.
"I have no reason to be looking beyond the next match, [I'm taking it] every point at a time," Young told the BBC when asked about his chances.
Of the heatwave Britain is baking through, which amounts to normal weather for the Atlanta-based world number 55, Young said: "Enjoy it while you can, it's fun weather to play when it's like this."