LONDON - Four things to know about Thursday, Day 6 of the London Olympics:

* Gabby Douglas lights up gym with another gold.

* One more time: Phelps takes 200 IM again.

* Anthony keys record-setting performance for US hoops.

* Probe into Olympic badminton flap widens.

Now this is fierce.

Gabby Douglas became the third straight American to win gymnastics' biggest prize when she won the all-around Olympic title on Thursday. She finished with a score of 62.232, about three-tenths ahead of Viktoria Komova of Russia.

It's her second gold medal of the London Games, coming two nights after she and her "Fierce Five" teammates gave the United States its first Olympic team title since 1996.

Douglas brought the house down with her energetic floor routine, and U.S. pals Jordyn Wieber, McKayla Maroney and Kyla Ross jumped to their feet and cheered when she finished. Douglas flashed a smile and coach Liang Chow lifted her off the podium.

Michael Phelps also had a smile on his face after he added to his medal collection with his first individual gold medal of the London Games.

The U.S. star set the tone right from the start to become the first male swimmer to win the same individual event at three straight Olympics, capturing the 200-meter individual medley for his 20th career medal - and 16th gold. Teammate Ryan Lochte settled for silver and Hungary's Laszlo Cseh took the bronze.

Americans Rebecca Soni (200 breaststroke) and Tyler Clary (200 backstroke) also won. Soni lowered her own world record with a time of 2 minutes, 19.59 seconds in the final.

Ranomi Kromowidjojo of the Netherlands took the 100 freestyle, clocking 53.00 to improve on her own Olympic record.

The U.S. men's basketball team returned to the court and put together a dominant performance in a 156-73 win against Nigeria.

Carmelo Anthony scored 37 points to set the American Olympic mark for points in a game - in less than three quarters. He made 10 of 12 3-point attempts.

The U.S. also set the Olympic record for points in a game and points in a half (78). The Americans bettered the U.S. records as well for 3-pointers (26), field goals (59) and field-goal percentage (71).

The Olympic badminton controversy continued for a third day, with the IOC demanding a deeper investigation into the scandal and an embattled Chinese player appearing to quit the tarnished sport.

Four doubles teams were kicked out of competition Wednesday, and the women — the top-seeded pair from China, two pairs from South Korea and one from Indonesia — were also set to have their accreditations removed by their national Olympic bodies and sent home.

Defending Olympic champion Yu Yang of China went further by apparently announcing her retirement from badminton.

“This is my last game,” read a posting on a verified account for Yu on the Tencent microblogging service. “Farewell Badminton World Federation. Farewell my dear badminton.”

The rest of the Olympic action Thursday:

Kayla Harrison tried to keep it together. Once the national anthem started, so did the tears.

Harrison defeated Britain’s Gemma Gibbons to win the United States’ first judo gold medal in Olympic history, taking the 78-kilogram title.

The 22-year-old Middletown, Ohio, native who lives in suburban Boston went to the medal podium determined not to cry. After one note of “The Star-Spangled Banner,” she succumbed.

“I’m just so honored to be America’s first gold medalist, and so happy to realize my dream,” she said.

Tagir Khaibulaev of Russia won the men’s 100-kg gold, beating Beijing champion Tuvshinbayar Naidan of Mongolia with a match-ending ippon throw.

TENNIS

Roger Federer is still rolling in his pursuit of his first Olympic singles medal.

Federer beat American John Isner 6-4, 7-6 (5) and will play No. 8-seeded Juan Martin del Potro in the semifinals.

Serena Williams, another reigning Wimbledon champion who is seeking her first Olympic singles medal, advanced by beating former No. 1 Caroline Wozniacki of Denmark 6-0, 6-3. Williams’ opponent in the semifinals Friday will be top-seeded Victoria Azarenka, who beat Angelique Kerber 6-4, 7-5.

Russians Maria Sharapova and Maria Kirilenko will meet in the other women’s semi.

Novak Djokovic also advanced on the men’s side and next plays Britain’s Andy Murray.

VOLLEYBALL

Captain Clay Stanley scored 19 points and the U.S. men’s team defeated Brazil 3-1 in a preliminary-round rematch of the Beijing final.

The 23-25, 27-25, 25-19, 25-17 victory extends the United States’ Olympic winning streak to 11 matches.

CYCLING

Germany’s Miriam Welte and Kristina Vogel checked a computer screen several times before erupting in laughter.

Yup, Olympic champions.

Welte and Vogel won the gold in sprint track cycling after the Chinese duo of Guo Shuang and Gong Jinjie was disqualified for a lane change in the final.

The Chinese pair had finished a victory lap and was celebrating when the announcement was made.

Britain broke its own world record set earlier in the day to win its second straight gold medal in the men’s team sprint. The team of Philip Hindes, Jason Kenny and Chris Hoy posted a time of 42.600 seconds, bettering the mark of 42.747 they had set in the previous round.

BEACH VOLLEYBALL

All four American teams — two in the men’s tournament and two in the women’s — finished the round-robin atop their pools, with defending gold medalists Todd Rogers and Phil Dalhausser beating the Czech Republic in the finale.

Defending world champions Emanuel and Alison of Brazil struggled through an extended first set to beat Italy and win their group. The Brazilians beat Paolo Nicolai and Daniele Lupo 26-24, 21-18.

Americans Jennifer Kessy and April Ross finished 3-0 with a 21-19, 19-21, 19-17 victory over Spain. Kerri Walsh Jennings and Misty May-Treanor finished their pool play with a No. 1 seed on Wednesday, as did Jake Gibb and Sean Rosenthal.

WATER POLO

Tony Azevedo scored four goals and the U.S. men’s team beat Britain 13-7 to remain undefeated at the London Games.

The Americans are on top of Group B with six points, one ahead of gold medal-favorite Serbia, with two preliminary stage matches to go.

Serbia played to an 11-11 draw with Montenegro. The Serbs face the U.S. on Saturday.

BOXING

U.S. boxers are dropping out of the Olympic tournament at a rapid rate.

The American skid reached seven straight bouts with narrow defeats for lightweight Jose Ramirez and middleweight Terrell Gausha. Only welterweight Errol Spence and flyweight Rau’shee Warren — who hasn’t fought yet — are still alive.

ROWING

The United States defended its title in the women’s eight, maintaining its six-year dominance of the high-profile event.

The Americans won in a time of 6 minutes, 10.59 seconds. Canada finished a half-length behind in second and the Netherlands took the bronze.

The U.S. hasn’t lost a competitive race in the eight since winning the world title in 2006.