Wimbledon star forgets rules during match and has to apologise to opponent

American star Danielle Collins had a lapse in her memory and temporarily forgot the rules of tennis against Iga Swiatek on Saturday. As she prepared to return a serve from the Polish player, it appeared that Collins was the only person on Wimbledon's Centre Court who didn't realise she'd made a mistake.

Midway through a first set largely controlled by Swiatek at the All England Club,a first serve was fired down the court towards Collins and called out. It quickly became clear that Collins either hadn't heard the call or momentarily forgot the rules of the game she's been playing professionally for almost a decade however.

As she strolled over to the other side of the baseline, seemingly ready to face a serve from Swiatek from the opposite direction whispers started to circulate and Swiatek remained in her original position, bouncing the ball and getting ready for her second serve.

The murmurs turned into laughter when Collins looked up, recognised her mistake and sheepishly jogged back to the correct side of the baseline.

She even shouted "Sorry, Iga!" across the court in an attempt to make light of the situation.

READ MORE: Wimbledon star lifts up skirt to make point during dress code row with umpire

READ MORE: Wimbledon star crashes out in tears after having blood pressure taken in medical timeout

On the other side of the net, Swiatek remained focused, swiftly winning the first set and then the match.

Despite her high ranking in women's tennis, Wimbledon has traditionally not been a successful tournament for former world No. 1 and five-time Grand Slam winner Swiatek.

Despite her victories in the French Open and the US Open, as well as reaching the semi-finals of the Australian Open, Swiatek's best performance at Wimbledon has only been to reach the quarter-finals, making it her least successful Slam on the calendar.

However, since arriving for this year's tournament, Swiatek has been in top form. After triumphing over Polina Kudermetova and Caty McNally in the first two rounds, she completely outplayed Collins to secure her place in the round of 16.

The Polish player, who was the top seed at last year's Championships, broke early in the first set to lead 2-1 and then again to extend her lead to 4-1. Her varied shots had Collins scrambling all over the court, with the 31 year-old having to pick herself up from the grass more than once.

Another Swiatek break and hold followed at the very start of the second set, and she fashioned another in the last game of the match to clinch a 6-2 6-3 victory in an hour and 15 minutes.