Paris - Fourth seed Grigor Dimitrov reached the French Open second round on Sunday, even if he wasn't exactly sure who he was facing on the other side of the net.
Dimitrov had been drawn to face experienced Viktor Troicki in the tournament opener on Philippe Chatrier Court.
However, just before he was due to go on court, Troicki withdrew with a back injury, allowing Egyptian world number 182 Mohamed Safwat to make his Grand Slam debut.
In the process, he became the first Egyptian since Tamer El Sawy at the 1996 US Open to feature in a major.
"I was warming up and my coach said, 'hey look' and we saw up on the board that I was playing a different opponent," said 27-year-old Dimitrov, a former Wimbledon semi-finalist who knew something of Safwat's game from matches during their junior days.
"I didn't expect that. I found out about 30 minutes before, but it is what it is. You have to be ready."
Safwat, 27, had lost in the final round of qualifying to Guido Andreozzi of Argentina last week in what was his eighth futile attempt to make the main draw of the majors.
He has won just one high-profile match in 2018 in the Davis Cup in February and his career earnings of $350,000 pale in comparison to Dimitrov's $15 million.
There was a world of difference between the two men on a sun-kissed centre court on Sunday in the first two sets.
But Safwat, one of seven lucky losers in the men's draw, then overcame blisters on his right hand to put up a solid challenge in the third set before Dimitrov raced through the tiebreaker for a 6-1, 6-4, 7-6 (7/1) win.
Dimitrov next faces either Jared Donaldson of the United States or Chile's Nicolas Jarry.
"I only heard I was playing an hour before the match," said Safwat.
"I was warming up, I signed in as a lucky loser and I was told I might be on court at 11 o'clock.
"I dealt with it as best I could. I had never set foot on that court before."
A rule change this year has helped the cause of defeated qualifiers at the Slams.
If a player withdraws injured before their scheduled first-round match, they still receive half the prize money while the lucky loser takes the other half.
Defending champion Rafael Nadal, who starts his campaign for an 11th Roland Garros title on Monday, will also face a lucky loser.
Italy's world 130 Simone Bolelli moved into the draw after Ukraine's Alexandr Dolgopolov pulled out with a wrist injury.
Meanwhile, women's fourth seed Elina Svitolina, a quarter-finalist in Paris in 2015 and 2017, overcame a first set 1-5 deficit to see off Australia's Ajla Tomljanovic 7-5, 6-3.
"To be ready for a Grand Slam is always the goal, the main goal for me," said the 23-year-old Ukrainian, also a quarter-finalist at the Australian Open this year.
"I try to do everything what's in my power to play my best game on the Grand Slams."
Svitolina next faces either 2010 champion Francesca Schiavone, the 37-year-old Italian, or Slovakia's Viktoria Kuzmova.
Other early winners on Sunday included Estonian 25th seed Anett Kontaveit who downed Madison Brengle of the United States 6-1, 4-6, 6-2.
Kontaveit defeated Australian Open champion Caroline Wozniacki on her way to the semi-finals in Rome last week.
She was also a semi-finalist on clay in Stuttgart while also beating Venus Williams in Madrid.
Later Sunday, German second seed Alexander Zverev starts against Ricardas Berankis of Lithuania.
Results from day one of the French Open at Roland Garros on Sunday (x denotes seeding):
Grigor Dimitrov (BUL x4) bt Mohamed Safwat (EGY) 6-1, 6-4, 7-6 (7/1)
Damir Dzumhur (BIH x26) bt Denis Kudla (USA) 6-4, 6-2, 6-2
Ekaterina Makarova (RUS) bt Zheng Saisai (CHN) 6-4, 6-1
Petra Martic (CRO) bt Wang Yafan (CHN) 6-2, 6-3
Elina Svitolina (UKR x4) bt Ajla Tomljanovic (AUS) 7-5, 6-3
Anett Kontaveit (EST x25) bt Madison Brengle (USA) 6-1, 4-6, 6-2