Two gaping holes were blasted into the women’s draw at Wimbledon on Sunday (Australian time) as defending champion Iga Swiatek was outplayed by Filipino crowd-pleaser Alexandra Eala and second seed Elena Rybakina was sent packing by Belgian Elise Mertens.

There was American disappointment on the day of the nation’s 250th anniversary of the Declaration of Independence as Serena Williams, one of its greatest-ever athletes, withdrew from her eagerly awaited doubles match with sister Venus because of injury.

Serena and Venus Williams. Tim Clayton

Williams, who returned to the tournament after a four-year absence but lost to Australia’s Maya Joint in the singles, said on Instagram she was “heartbroken to have to withdraw”.

Disgruntled Polish third seed Swiatek lost a titanic first-set battle that lasted almost 90 minutes and had no answer to a fearless Eala after that as she lost 7-6(9), 6-2.

Rybakina, the 2022 champion who doubled her grand slam tally this year by winning the Australian Open, also fell away badly after a close first set, going down 7-6(4), 6-1 to Mertens, who has reached the last 16 for the fourth time.

“Definitely I need to analyse and change something because it’s not working,” said Rybakina, for whom a run to the quarter-finals here could have seen her become world No.1.

There were July 4 fireworks on Centre Court as 26th seed Madison Keys upset last year’s runner-up Amanda Anisimova, seeded six, 3-6, 6-2, 6-3 in an all-American blockbuster.

Keys, on a roll on the grass after her title run in Eastbourne last week, was one of eight American singles players in action on the nation’s big day.

There was further US success as qualifier Ashlyn Krueger enjoyed a comprehensive 6-3, 6-2 victory over Ukraine’s Daria Snigur, but 23rd seed Emma Navarro went out to Ukraine’s Marta Kostyuk in three sets.

The shocks did not continue to the men’s draw, though, where second seed and newly crowned French Open champion Alexander Zverev maintained his impressive start with a 6-2, 7-6(4), 6-4 victory over American Marcos Giron.

With defending champion Jannik Sinner already through, Italy began the day with hopes of four men in the last 16 of a grand slam for the first time since the 1947 French Open.

Roland-Garros runner-up Flavio Cobolli, seeded nine, lost the opening set 6-0 against Russia’s Karen Khachanov but rallied to win in five, prevailing 0-6, 7-6(4), 6-7(5), 6-2, 6-2.

Iga Swiatek during her loss to Alexandra Eala. Getty

Cobolli will face Australian Alex de Minaur next after he beat American Zachary Svajda 6-2, 5-7, 6-2, 6-4.

Lorenzo Sonego could not join the Italian surge, though, despite a strong start against American sixth seed Taylor Fritz, losing 4-6, 6-3, 6-4, 7-6(5).

Eala went toe-to-toe with Swiatek in a gripping first set and saved a set point in the tiebreak as her opponent netted a forehand, the Pole laughing sarcastically and shouting at her entourage in the stands.

Eala remained composed in the second set as she sprinted clear and held her nerve to claim a famous win.

While Eala’s joy was uncontained, six-time grand slam champion Swiatek slumped off, trying to digest another disappointing loss.

“Honestly, I don’t care anymore about the results. I’ve been so focused on them that it’s hard to continue like that,” she told reporters. “So I’m really trying to let it go.”