Carlos Alcaraz begins the defence of his Wimbledon title on Monday as two-time champion Andy Murray decides whether or not to call a halt to his All England Club singles career.
As action got under way, world number three and Australian Open champion Aryna Sabalenka was heading home after withdrawing from the tournament with a shoulder injury.
Alcaraz, still only 21, is chasing his fourth Grand Slam title and hopes to become just the sixth man after Rod Laver, Bjorn Borg, Roger Federer, Rafael Nadal and Novak Djokovic to win the French Open and Wimbledon back-to-back.
"I know that there's going to be a really difficult and big challenge for me, but I think I'm ready to do it," said the third-seeded Spaniard.
Alcaraz faces 21-year-old Estonian qualifier Mark Lajal, who had never won a Grand Slam qualifying match let alone a main draw tie before last week.
Lajal, the son of a motocross rider, has just two wins on the ATP tour in his career but if his playing statistics do not stand out, then his dreadlocked, blond hairstyle certainly turns heads.
"I've had them for a very long time. It has kind of become a big part of me and my image. A lot of people know me just from my dreads. I think it's cool," said the world number 269.
This time last year, Lajal was losing a first-round match at a second-tier Challenger event in the US and earning a paltry $780.
For making the first round at Wimbledon he is guaranteed $75,000.
Two-time semi-finalist Sabalenka is one of seven players to have pulled out since the draw was made.
Sabalenka had admitted she was not 100 percent fit after suffering a shoulder injury that she described as "a rare one" and is replaced by Russian lucky loser Erika Andreeva.
Among early winners were eighth-seed Casper Ruud, who has never been past the second round, and 10th seed Grigor Dimitrov, a semi-finalist in 2014.
World number one Jannik Sinner, a semi-finalist in 2023, starts against Yannick Hanfmann, the German world number 110.
Sinner got the better of him in their only meeting at the US Open in 2023, where the German won just five games in their first-round clash.
The 22-year-old Sinner won a maiden Slam at the Australian Open and then deposed Djokovic as world number one, becoming the first Italian man to reach such heights.
Sinner arrives in London having captured his first grass-court title in Halle.
Murray, champion in 2013 and 2016, will reveal later Monday if he will play singles at his farewell Wimbledon.
The former world number one underwent surgery to remove a cyst on his spine last week and admitted he still has not fully recovered feeling in his leg as a result.
"It's kind of like if you sleep on your arm funny, you wake up and you've got a dead arm," said the 37-year-old.
Murray, whose 2013 triumph ended Britain's 77-year wait for a men's champion at Wimbledon, is due to face Czech world number 39 Tomas Machac on Tuesday.
If he cannot make that date, he still hopes to play doubles with brother Jamie before bringing the curtain down on his Wimbledon career, which began 19 years ago.
"I'm hoping maybe for a bit of closure. I just want the opportunity to play one more time out there hopefully on Centre Court and feel that buzz," he said.
Elsewhere on opening day, women's second seed and US Open champion Coco Gauff takes on American compatriot Caroline Dolehide.
Four-time major winner Naomi Osaka tackles Diane Parry of France in her first appearance at Wimbledon since 2019.
Osaka, who only returned to the tour at the start of the season afer maternity leave, is ranked at 113 and required a wild card to play at Wimbledon.
At the recent French Open, she gave world number one Iga Swiatek a mighty scare, holding a match point in their second-round clash before the Pole prevailed.
"People tell me I have the game for grass. I just need some luck," said the Japanese star.
