The Madrid Open has been cancelled after organisers were advised by the Spanish health ministry not to hold it amid the city's "deteriorating" coronavirus situation.
The clay-court event was set to start in the Spanish capital on 12 September.
"We have no choice but to cancel the tournament due to the complex situation that Covid-19 continues to generate in every regard," said organisers.
Spanish great Rafael Nadal was among the players who signed up to play.
Spain has recorded more than 302,000 cases of coronavirus since the start of the pandemic, and 28,498 deaths, according to the latest figures released on Tuesday.