By Shrivathsa Sridhar and Martyn Herman

LONDON (Reuters) -Women's top seed Aryna Sabalenka fought off inspired home favourite Emma Raducanu in a cauldron-like Centre Court atmosphere to keep her Wimbledon quest on track but it was the end of the road for two other Grand Slam champions on Friday.

Sabalenka ended British interest in the women's singles, edging a ferocious contest under the roof after requiring eight set points in the opening set and then roaring back from a 4-1 deficit in a sizzling second.

"Wow! What an atmosphere, my ears are still hurting, it was super loud," a relieved Sabalenka said on court after wrapping up the win on her third match point.

Spain's Carlos Alcaraz, chasing a third successive Wimbledon title, was also put through the wringer by Germany's Jan-Lennard Struff before sealing a last-16 spot with a 6-1 3-6 6-3 6-4 win.

A record 36 seeds in the men's and women's singles failed to reach round three and the upsets continued on Friday as women's sixth seed Madison Keys, the Australian Open champion, and four-time major winner Naomi Osaka departed.

Japan's Osaka looked every bit the Grand Slam great for a set before losing 3-6 6-4 6-4 to Russia's Anastasia Pavlyuchenkova. American Keys racked up 31 unforced errors in a 6-3 6-3 loss to Germany's Laura Siegemund, at 37 the oldest woman left in the singles draw.

Sabalenka is the only top-10 seed left in the top half of the draw and, with only three remaining in the bottom, she might be starting to think this could be her year.

If she does win the trophy to add to her two Australian Opens and one U.S. Open, she will look back on Friday night under the Centre Court roof as perhaps the turning point.

Had she lost the opening set the partisan crowd might well have roared former U.S. Open champion Raducanu to victory.

Even after clinching the first set with a deft volley, Sabalenka found herself in trouble as 40th-ranked Raducanu blazed ahead and had a point for a 5-1 lead. But she then switched on the after burners to overwhelm the flagging Briton.

"Emma played such incredible tennis and she pushed me really hard to get this win," said the 27-year-old Belarusian. "I had to fight for every point to get this win."

HOME HOPES

Raducanu's loss ended hope of a British hat-trick on day five after Sonay Kartal and Cameron Norrie sailed through to the last 16 in impressive fashion.

Local favourite Kartal moved on with a remarkable display against French qualifier Diane Parry, claiming nine games in a row to come from 1-4 down to win 6-4 6-2.

Norrie kept the home flag flying in the men's singles by beating Italian Mattia Bellucci 7-6(5) 6-4 6-3 to set up a meeting with Chilean qualifier Nicolas Jarry, who overcame Brazilian wonder kid Joao Fonseca 6-3 6-4 3-6 7-6(4).

Kartal had earlier reeled off nine games in a row after a slow start to beat French qualifier Diane Parry 6-4 6-2 and set up a clash with Russian Pavlyuchenkova.

French Open winner Alcaraz extended his winning run to 21 matches by beating Struff but it was a Jekyll and Hyde performance as he again showed vulnerability.

"I was suffering in every service game... 0-30s and breakpoints down. It was stressful. Every time he could push me, he did. I was trying to survive," Alcaraz said.

The 22-year-old will face Russian 14th seed next after he beat French qualifier Adrian Mannarino 7-5 6-2 6-3.

Taylor Fritz, Ben Shelton and Amanda Anisimova ensured there would be some Fourth of July celebrations for Americans.

After being taken the distance in his first two matches, fifth seed Fritz had a slightly easier ride as he beat Spain's Alejandro Davidovich Fokina 6-4 6-3 6-7(5) 6-1 to reach the last 16 where he will face unseeded Australian Jordan Thompson.

Despite spending more than nine hours on court, Fritz said he felt fresh ahead of his Sunday assignment with Thompson.

"This is going to sound crazy," said Fritz, who has been suffering tendinitis in his knee and had to deal with a bruised arm after a fall. "My body is actually feeling better after each match. I feel like somehow it felt the worst after my first round but now it's getting better."

Anisimova, the 13th seed, also reached the fourth round with a 6-3 5-7 6-3 win over Hungarian Dalma Galfi.

Shelton, who was left seething after his second-round clash with Rinky Hijikata was suspended late on Thursday with him about to serve for the match, needed around one minute to finish the job on Friday, hitting three aces and an unreturned second serve to take his place in the last 32.

French showman Gael Monfils also had to resume his match but the 38-year-old could not prevent a 6-4 1-6 4-6 7-6(5) 6-4 defeat by Hungary's Marton Fucsovics.

"I don't really know. I wish I could win this match today but that's sport. I'm going to rest a couple of days and go back on court and try to be ready for the U.S. tour."

It was the end of the road for Monfils's wife Elina Svitolina too as the Ukrainian 14th seed fell 6-1 7-6(4) against 24th seed Elise Mertens.

(Reporting by Shrivathsa Sridhar in London; editing by Clare Fallon)