Dan Evans and Cameron Norrie have both been knocked out in the first round of the Cincinnati Open.
Evans won his first ATP 500 title at the Citi Open this month but was beaten 6-4 6-3 by Italy’s Lorenzo Musetti.
British number one and 13th seed Norrie, 27, was defeated 6-3 4-6 3-6 by Frenchman Gael Monfils.
Carlos Alcaraz’s opening set against Jordan Thompson was briefly halted by rain before the world number one won 7-5 4-6 6-3 in the second round.
Evans, who is the British number two, was set to play on Monday but heavy rain in Cincinnati delayed his match with world number 18 Musetti until Tuesday.
The 33-year-old was also beaten in the opening round of the Canadian Open last week as he prepares for the US Open which starts 28 August.
Alcaraz, 20, is set to defend his title having won his first Grand Slam at Flushing Meadows last year but the Spaniard was beaten by Tommy Paul in last week’s Canadian Open quarter-finals before claiming a hard-fought win over Australian qualifier Thompson here.
“I had never played him and the start-stop was not easy,” Alcaraz said. “It was not easy to wait for the rain.
“I had to play my best level at the end. He played aggressive, I’m glad to get through. It was a long day waiting to play and then find rain in the first set. I’m hoping for better conditions in the next round.”
In the third round Alcaraz will either have a rematch with American Paul or face Ugo Humbert of France.
Musetti will face Russian third seed Daniil Medvedev in the second round while Monfils will take on Australia’s Alex de Minaur.
Earlier, Andy Murray pulled out of the tournament in Cincinnati as he is still suffering from the abdominal strain that forced him to withdraw from the Canadian Open.
Jabeur wins first match since Wimbledon final
In her first match since losing the Wimbledon final to Czech Marketa Vondrousova on 15 July, Ons Jabeur secured a 6-3 6-7 (2-7) 7-6 (7-2) win over Ukrainian Anhelina Kalinina.
Tunisia’s number five seed, who received a first-round bye, had to fight back from 5-1 down in the third set to reach the third round.
“It was very tough, but I’m glad that I kept fighting, kept playing point by point, and that I got the win in the end,” she said.
“Some situations that I went through during this match definitely helped get me back into the hard-court season. I will try to keep going, keep playing more matches. The more matches I play, the better.”
Also in the second round of the women’s draw, the USA’s Sloane Stephens beat French sixth seed Caroline Garcia 4-6 6-4 6-4.
Wildcard Caroline Wozniacki’s second event back after three years away ended in defeat by lucky loser Varvara Gracheva in the first round.
Former world number one Wozniacki, 33, announced she would return to tennis in June after retiring in 2020 but she was beaten 6-4 6-4 in 95 minutes by France’s Gracheva.
“I still have about 10 days to prepare for the US Open,” Wozniacki said. “There are quite a few things that I feel like I need to do better.”
Number 11 seed Barbora Krejcikova of the Czech Republic was beaten 6-3 7-5 by Belarus’ Victoria Azarenka while Swiss number 13 seed Belinda Bencic was upset 6-4 3-6 2-6 by Spanish qualifier Cristina Bucsa.
