5 Things to Know About Tennis Player Kei Nishikori

In what is being considered a stunning upset, a relatively unknown Japanese tennis player, Kei Nishikori, defeated the No.1 ranked Novak Djokovic in the 2014 U.S. Open tennis championship on Saturday – becoming the first Japanese man to reach a Grand Slam final in tennis history.

So exactly who is this hot up-and-comer? We’ve compiled five things to know about the guy who just seriously shook up the tennis world.

Jessica Simpson's Big Wedding, Khloé Kardashian's 30th Birthday & More Weekend News

Celebs spent their time well over 4th of July weekend, getting hitched, partying in Vegas, catching a tennis match and relaxing on the beach. Here’s the news you may have missed while watching fireworks and chilling on the sand:

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Tennis Stars: Chris Hemsworth, Victoria Beckham, Hugh Jackman & More Watch Wimbledon Men's Finals

Watch a Tennis Match from Roger Federer's Point of View (VIDEO)

Ever wanted to play tennis like Roger Federer?

Well, thanks to Google Glass, you can get a small glimpse of what it’s like to be a world-class tennis player.

Celebrity Baby Boom! Kristin Cavallari, Kerry Washington and More Stars Welcomed Newborns

It’s a celebrity baby boom!

Over the course of about a week, seven stars have announced the births of their little bundles of joy. From Kerry Washington to Bruce Willis, A-listers are introducing fans to the newest additions to their families.

To make sure all the new moms and dads get the congrats they deserve, PEOPLE recapped the week’s biggest baby news:

Roger Federer Welcomes Twin Sons Leo and Lenny

The tennis star, 32, and his wife Mirka welcomed twins – again! – on Tuesday, May 6, he announced on Twitter

Third Child on the Way for Roger Federer

“Mirka and I are very happy to share the news that Myla & Charlene will be big sisters in 2014! Happy Holidays,” the tennis champ writes

Andy Murray Defeats Roger Federer to Win Olympic Gold

Tennis player Andy Murray won Olympic gold (and revenge!) Sunday when he unseated world champion, Roger Federer, who beat him at Wimbledon last month.

After four losses (three to Federer) in the Grand Slam finals, Murray surprised spectators when he defeated Federer 6-2, 6-1, 6-4 to win the men’s single finals at the Summer Games.

Kate & Pippa Middleton Watch Wimbledon Men's Final

It was something of a sister act for the Duchess of Cambridge on Sunday at Wimbledon: She had Pippa by her side when she cheered on Brit Andy Murray at the men’s final.

Big tennis fans (and players), Kate, 30, and Pippa, 28, clapped enthusiastically as Murray took the early lead against Roger Federer, and they were seen sharing a giggle in the royal box above Centre Court.

Roger Federer Predicts Tiger's Comeback

Tiger Woods’s pal Roger Federer has spoken to the elusive golfer and believes his scandal-plagued friend will soon return to the sport.

Federer predicts in an interview with French sports paper L’Equipe published Friday that Woods will make a comeback “as the wonderful golfer we know.”