"Had my regrets about not being down at Wimbledon today, but they have miraculously disappeared" - Tennis fans react to Sir Cliff Richard's performance at Wimbledon

The centenary celebrations for Wimbledon's Centre Court saw many special guest appearances on Sunday, the first officially scheduled middle Sunday in the tournament's history. Among those present was Sir Cliff Richard, a British music icon and long-time tennis enthusiast, whose musical performance on Centre Court drew varied reactions from tennis fans on social media.

The 81-year-old singer got a section of the crowd grooving along to him singing his No. 1 hit song 'Summer Holiday' in the iconic tennis arena. However, there were fans as well as critics of his singalong at SW19.

"Had my regrets about not being down at Wimbledon today, but they have miraculously disappeared," one fan wrote on Twitter.

"Oh good god. Reckon Cliff Richard has got himself a crying, talking, sleeping walking out Wimbledon crowd right there," another fan expressed.

Born as Harry Rodger Webb, the Brit showed an interest in music at a young age and quickly made it his profession after completing his schooling. He then changed his name to Cliff Richard, taking the advice of Harry Greatorex, and soon started to taste success as the lead singer of the group The Drifters. He later parted ways with the group.

After years of success in the music industry and also a stint as a 'movie star', Richard was honored with the 'Officer of the Order of the British Empire' in 1980. Richard is one of the best-selling artists in the UK, behind just Elvis Presley and The Beatles.

While many ridiculed Richard's performance, there were those who also spoke out in support of the 81-year-old music legend.

"The "jokes" some people are making about Cliff Richard singing at #Wimbledon are just mean-spirited, plain nasty, and tinged with ageism. They think they're being all funny and clever, but really they're just ridiculing an 81 year old man. It's just not nice," one such fan expressed.

Which tennis superstars graced Wimbledon's Centre Court centenary celebrations with their presence?

Past champions during the Centre Court centenary celebrations

Past champions at Wimbledon were introduced and honored during the Centre Court centenary celebrations. Tennis legends such as Billie Jean King, Margaret Court, Stefan Edberg, Venus Williams, Rod Laver, Rafael Nadal, and Novak Djokovic were present, among others. The final introduction was reserved for the tournament's most decorated champion, Roger Federer, who has won the tournament eight times.

The Swiss great had a few words to say after the crowd welcomed him back on Centre Court with a huge round of applause.

"This court has given me my biggest wins, my biggest losses," Federer said, adding, "One of my highlights has of course been in 2001, walking out here with Pete Sampras, who I'd like to give a big shoutout to - he's also won and inspired a lot of us to play and just also to be successful here and represent the sport well and I hope I did that. I hope I can come back, like you said, one more time."

Tennis fans waited with great anticipation for a Federer-Nadal moment during the ceremony and were treated to a picture of the two greats who have a combined tally of 42 Grand Slam titles between them.