Puerto Rico's Puig wins gold, Murray faces del Potro in tennis final

​Monica Puig has won Puerto Rico's first-ever Olympic gold medal, upsetting Germany's Angelique Kerber 6-4, 4-6, 6-2 in the women's singles final on Saturday.

• SCHEDULE & RESULTS: Tennis at Rio 2016

• WATCH: Puerto Rico's Monica Puig makes history

Kerber had survived three match points down 5-1 in the third set, before Puig made good on the fourth when the German's forehand went wide.

Puig had 54 winners throughout the match and just 33 unforced errors. The 22-year-old is currently the WTA's 34th-ranked player while Kerber is ranked No. 2.

For Kerber, this is the second straight major championship loss, having also reached the final at Wimbledon before losing to Serena Williams.

• WATCH: Kvitova beats Keys to take Rio bronze

Czech tennis player Petra Kvitova won the bronze medal in women's singles in Rio on Saturday, while Juan Martin del Potro will go against defending champ Andy Murray for gold on the men's side on Sunday.

Two-time Wimbledon champ Kvitova beat American Madison Keys in three sets to take the bronze. She won 7-5, 2-6, 6-2 on Saturday, running away with the third set after dropping the last four games of the second.

Since winning her second Wimbledon title in 2014, the Czech lefty hasn't been beyond the quarter-finals at a major. In the first three of this year, she didn't even make it past the third round, with her ranking falling to 14th.

Keys is a career-best No. 9 in the world, but for the second straight match the 21-year-old couldn't capitalize on her opportunities against a more experienced opponent. She failed to convert two set points in the first.

Nadal ousted

On the men's side of the draw, 2008 champ Rafael Nadal of Spain was ousted by Argentine's del Potro 5-7, 6-4, 7-6 (5) on Saturday.

Nadal already won gold on the doubles side, and will play Japan's Kei Nishikori for bronze Sunday on the singles side.

"I gave it all I had," said the Spaniard, "and the only thing left to do is to congratulate del Potro for his victory."

• WATCH: Defending champ Andy Murray advances to gold medal match
• WATCH: Juan Martin del Potro defeats Rafael Nadal to advance to gold medal match

Del Potro won bronze in London, and will have a chance to dethrone the reigning Olympic champion in Murray in a five-set final.

His 2009 U.S. Open win to date is the highest achievement in the 27-year-old's career, which has been marred by wrist surgeries the past two seasons. He's already shown that when healthy he's among the best players in the world, having eliminated No.1 seed Novak Djokovic in the opening round.

Now he has a chance to add to his trophy collection.

"It means something very, very big in my career. It would be the same as the U.S. Open. Maybe even better," said del Potro. "I didn't expect to reach the final, beating Djokovic and Rafa but I did, and I get a medal, and it's amazing for me."

Murray can become the first player in Olympic history to win two gold medals in singles if he can gold off the Argentinean.

"It would mean a lot, obviously," said Murray, who's now won a career-high 17 straight matches. "It's obviously not an easy thing to do. That's why it's not been done before."

With files from The Associated Press