Bernard Tomic believes he and Davis Cup team-mate Nick Kyrgios are unfairly branded "tankers", saying they fight for every point - even if it doesn't always look like it.

Tomic also let his actions do some talking on Thursday with a gutsy, come-from-behind victory over Spain's Fernando Verdasco lifting him to the quarter-finals at the Queen's Club and helping dispel his tanking reputation.

The 23-year-old recovered from a first-set tiebreak thrashing on Thursday to defeat the tricky former world number seven 6-7 (7/2), 6-4, 6-4 and book a clash with Luxembourg's Gilles Muller on Saturday morning (AEST) for a final-four spot.

For much of his career Tomic has been forced to face accusations of tanking.

The explanation, for him, is simple: his relaxed body language can be misinterpreted as not caring, when in fact he often uses it to lull opponents into a false sense of security.

"When you look at Nick and I, we don't return the greatest, so sometimes we're down 30-love, 40-15 in games, and when a guy hits a good serve, it tends to look like we walk [away from the serve]," he said.

"But we are really there [competing].

"People sometimes ... accuse me of tanking (but) sometimes that's the way I sort of come back into the match.

"So sometimes I think people misunderstand me.

"Sometimes I use being down in a match as opposed to being ready and on your feet, sometimes I like to change it and do it my way.

"And sometimes it looks that I'm not trying ... But really I'm competing mentally for every point."

It is Tomic's maiden quarter-final appearance at Queen's, and Thursday's result gave him a 4-1 record over the tricky Verdasco, who was at times unplayable but also piled up the errors in his search for scorching winners.

Tomic threw away a golden opportunity to take an early stranglehold on the match when, up 4-2 in the opening set, he allowed Verdasco to break back and ultimately force a tie-break.

Bernard Tomic has long battled with tanking accusations throughout his career. ( Getty Images: Clive Brunskill )

Verdasco, who had looked uncomfortable and miscued one forehand so badly that it exited the complex and landed in a neighbouring park, then sprung to life and demolished the Australian in the tiebreak with a barrage of winners that left Tomic standing with hands on hips staring at his support box and laughing in disbelief.

"Sometimes Fernando can play amazing and there is nothing you can do," Tomic said.

Tomic wasted little time in regaining parity, however, breaking Verdasco twice to secure a 4-0 lead en route to taking the second set.

He was quick to pounce in the decider as well, grabbing the break in the third game before serving out the match in two hours and two minutes.

Muller, meanwhile, played all of his get-out-of-jail cards in a stunning 3-6, 7-6 (18/16), 7-6 (9/7) win over seventh seed John Isner.

Muller, who holds a 3-0 record over Tomic, saved an incredible 10 match points against the big-serving Isner.

AAP