Emma Raducanu did something she 'was not meant to do' during a break in play against Qinwen Zheng on Friday. The Brit was kept waiting by her Chinese opponent in the first set of their Queen's quarter-final, and she pushed her luck with the chair umpire by cheekily taking an opportunity to stay sharp.

With Zheng 3-2 up and threatening to widen the margin with break point on Raducanu's serve, the Shiyan-born competitor halted the match and returned to her seat to put on a fresh pair of shoes. After standing and waiting for more than a minute, Raducanu smashed a practice serve down the court before Zheng had returned to the baseline.

Chair umpires are given a level of discretion over such incidents, but USTA rules state that 'a player should take all warm-up serves before the first serve of the match'.

And BBC commentator Annabel Croft was quick to recognise that Raducanu had done something crafty and got away with it. She said: "I don’t know if Raducanu is meant to hit a ball like that. She’s just practiced a serve and normally you’re not meant to do that!"

The unusual mid-match interruption was accompanied by a smattering of boos, as Queen's spectators voiced their disapproval at Zheng holding up proceedings. The 22-year-old offered a hand of apology before composing herself, winning a long battle at deuce and then clinching every remaining game in the set to take it 6-2.

There were further interruptions in the second set as the crowd grew restless with Zheng, who looked sheepish as she was forced to halt the game for a third time to tend to an issue with her racket, with the home favourite watching on perplexed.

Despite Raducanu holding a commanding lead at one point in the second set, top seed Zheng steadied the ship and fought back to win 6-2 6-4.

Raducanu went into Queen's hoping to build some grass-court momentum ahead of Wimbledon, her home Grand Slam. And she got off to a flying start, notching dominant straight-sets over Cristina Bucsa in the first round and Rebecca Sramkova in the second.

The victory over Sramkova ensured that Raducanu would return to British women's No. 1 status in the wake of the tournament, with Katie Boulter dropping back to No. 2.

However, Raducanu downplayed the importance of the rankings shift. "Tennis is a funny one," she said. "You know, some people lose 250 points one week, some people lose zero, some people lose 100. It's something that happens every single week."