Stan Wawrinka showed glimpses of his grand slam-winning form but was bundled out of the Queen’s Club Championships by former Queen’s Club champion Sam Querrey.

The Swiss squandered several set points in the opening set and although he took the second on a tiebreak he capitulated in the decider after dropping serve at 1-2, losing 7-5 6-7 (7-3) 6-1.

His frustration boiled over as he buried his racquet frame into the lush centre court turf, taking a sizeable divot in the process, before snapping it over his knee.

Big-serving American Querrey, champion in 2010, calmly ticked off the next three games to move into the quarter-finals where he will meet either top seed Marin Cilic or Gilles Muller.

Wawrinka’s ATP ranking has plummeted to 261 after his first-round loss at the French Open, having reached the final a year ago, but the good news is that his knees appear strong again after two surgeries last August.

He struck the ball with authority in the second set and played a solid tiebreak but his lack of sharpness told as he was sent packing by the fifth seed.

Querrey joined fellow American Frances Tiafoe in the last eight after he beat Argentine Leonardo Mayer 6-4 2-6 6-4.

Frenchman Jeremy Chardy maintained his impressive form on grass with a 7-6 (8-6) 6-3 defeat of young Russian Daniil Medvedev.