All 16 first round matches were played at the König-Pilsener-Arena with play finishing after midnight local time.

The top 32 players on the European Tour Order of Merit qualified for the event, which started in 2008.

First round matches were played over the best of 11 legs and although the majority of big names progressed comfortably, Englishman Cross was a notable exception as he was upset 6-3 by Kleermaker.

England's Joe Cullen, who started the event as top seed, was also surprisingly defeated, as he was knocked out 6-3 by Ireland's William O'Connor.

Michael Van Gerwen of The Netherlands, the current world number one, is aiming to win this competition for a fifth time and eased through to round two as he overcame Darius Labanauskas of Lithuania 6-1.

Last year's runner-up Gerwen Price of Wales also eased through his opening match as he beat Belgium's Kim Huybrechts 6-1.

Current world champion Peter Wright beat Germany's Gabriel Clemens 6-3 while the final match of the day saw Mensur Suljović of Austria overcome Daryl Gurney of Northern Ireland 6-2.

Portugal's Jose de Sousa also grabbed the headlines as he hit a nine dart finish in the second leg against Jeffrey de Zwaan of The Netherlands on the way to a 6-3 victory.

Despite Germany announcing new coronavirus restrictions yesterday, spectators were allowed to watch the action in Oberhausen, although it was very different to the traditional darts crowd, with the applause of mask-wearing spectators a far cry from the usual raucous support associated with the sport.

Second round action takes place tomorrow across two sessions to determine the last eight.