Rome - Britain's Andy Murray and world number one Novak Djokovic were among the players left patiently sitting it out on Saturday as rain delayed the Rome Masters semi-finals.
Murray, the second seed, is set to face French lucky loser Lucas Pouille as he bids to reach his first final in Rome, where he could meet top seed Djokovic for the second time in a week if the Serbian beats Kei Nishikori in their last-four match-up.
But intermittent rain throughout the morning in the Italian capital has upset the entire schedule, forcing organisers to pull the covers onto the courts.
Spain's Garbine Muguruza was due to meet American Madison Keys on Centre Court at midday 12;00, although they had yet to hit a ball in anger over 90 minutes after the scheduled start of their match.
A statement from organisers said: "The start of Saturday's play has been delayed due to light rain at the Foro Italico.
"Garbine Muguruza was due to get underway against Madison Keys in the women's semi-final at midday local time.
"Further updates to follow where possible."
Murray lost to Djokovic last week in the final of the Madrid Masters, and the Serbian underlined his form less than two weeks from the start of the French Open at Roland Garros with a hard-fought two-set win over Spanish rival Rafael Nadal late on Friday.
In the other women's semi-final, world number one Serena Williams faces Irina-Camelia Begu of Romania.