Jennifer Lopez's ex-husband Marc Anthony won Favourite Latin Artist.
Accepting his award, the singer said: 'Just because you're alive doesn't mean you're living. Don't forgt to live.'
J-Lo was also in the house, and no doubt the friendly exes managed to catch up backstage.
Winning formula: Taylor Swift accepts the Favorite Country Album award for Red and thanked her fans for their support
Golden girl: Taylor Swift shimmered as she accepted her award on stage
Nicole Richie and Kelly Osbourne took to the stage to present One Direction with an award.
Amazingly, the band won the award for best Pop and Rock album.
Keeping with the theme of speeches for the night, the band thanked their fans for their support, and Simon Cowell of course.
I don't believe it! Justin Timberlake accepts Favorite Pop/Rock Male Artist award onstage looking dapper in a suit and bow-tie
Helpful advice: Marc Anthony told the audience 'don't forget to live' as he accepted the Favorite Latin Artist
Rather than thanking a list of friends and colleagues, Macklemore & Ryan Lewis used their American Music Awards acceptance speech to send a message of tolerance.
Ben Haggerty, the rapper known as Macklemore, accepted the award for favorite rap/hip-hop album, then quoted Martin Luther King Jr. in a live satellite feed from the rap group's latest tour stop.
'Due to the fact that we are in Florida tonight accepting this award I want to acknowledge Trayvon Martin and the hundreds and hundreds of kids each year that are dying due to racial profiling and the violence that follows it,' he said.
Howdy there: Ke$ha performed with rapper Pitbull and appeared to be dressed as a cowgirl
The whole package: Pitbull performs his song Timber with Ke$ha at the 41st American Music Awards in Los Angeles
Fangirl: Taylor was visibly excited to see that Justin Timberlake had won an award and posed with him backstage
One man band: Interestingly, Justin Timberlake won the award for Soul and R&B
'This is really happening. These are our friends, our neighbors, our peers and our fans, and it's time that we look out for the youth and fight against racism and the laws that protect it.'
Florida became a focal point after Martin's killer was freed under the state's stand your ground law.
It was the first win of the night for Macklemore and Lewis, whose album The Heist has been an unexpected hit and made them the AMA's top nominees with six.
Reunion: Rapper Lil Mama performs Waterfalls with singers Tionne 'T-Boz' Watkins and Rozonda 'Chilli' Thomas of TLC
Legend: An image of Lisa 'Left Eye' Lopes was flashed up at the end of their performance
The award for longest acceptance speech went to Rihanna, who was given the Icon award.
Overwhelmed by the fact her mother Monica Braithwaite gave her the award, Rihanna took a trip down memory lane revealing her road to stardom.
Rihanna's mother gave a touching intro, praising her daughter for being 'strong'.
Shining bright: Rihanna accepts the award for Favorite Soul/R&B Female Artist at the 41st AMAs
Tribute: Rihanna's mother Monica Braithwaite payed a touching tribute to her daughter and presented her with the Icon Award
Sealed with a kiss: Rihanna gives a lengthy speech spurred on by her mother Monica
'Can we talk about how cute Rihanna's mom is?' Justin Timberlake asked while accepting one of his three awards, before oddly affecting a Caribbean accent.
'She's so proud of the Icon. I am too, Rihanna, I love you.'
Rihanna was one of the night's early competitive winners as well. She took favorite soul/R&B female artist.
Justin won soul/R&B album, soul/R&B male artist and pop/rock male artist.
Different style: Presenters Kelly Osbourne and Nicole Richie seemed to go for opposite looks as they awarded One Direction with a gong
Where are the Fashion Police? Kelly was not joined by her colleague Joan Rivers, instead sharing the stage with Nicole Richie
Stylish support: Heidi Klum wowed in a black laced gown as she took to the stage to present an award
Special night: Zayn Malik, Niall Horan, Liam Payne, Harry Styles, and Louis Tomlinson were thrilled to accept the award for Best Album
Dunce: Louis Tomlinson - clearly the life and soul of the band - plays around with the trophy at the event
This one's for you, Kendall! Harry Styles sings his heart out on stage with Liam Payne at the American Music Awards
While Katy was the early focal point of the awards show, she was easily eclipsed by divas Lady Gaga, Christina Aguilera and Jennifer Lopez, who also performed.
Katy said before the show she wanted to up her game, given the chance to open, and the whirling stage production was a wash of colors and movements before she disappeared in a puff of smoke.
One Direction were at times drowned out by screams during an understated performance of Story of My Life.
Mr President! Lady Gaga, 27, played sexy secretary to R. Kelly's cigar-smoking president in their AMA performance of Do What U Want on Sunday
Do What U Want! Gaga looked reminiscent of another presidential favourite, Marilyn Monroe, with coiffured hair and a sparkly silver number
Up close and personal: The talented duo got raunchy on the presidential desk
The decibel level was that way from the moment the British boy band arrived on the carpet, all smiles and dapper suits. Harry Styles stopped to take a picture with three fans.
Billy Ray Cyrus also mingled with fans, signing autographs and taking photos.
Many wondered how his daughter, Miley, would close things down with the final performance of the night. Most of the year's top performers were scheduled to take the stage, and Lady Gaga, Rihanna, Luke Bryan and Florida Georgia Line were still to come.
Change up: The former Mickey Mouse Club member swapped her sexy white dress for a subdued black one to perform Say Something during the show
Clean slate: The singer toned down her hair and makeup to sing the touching ballad
Collaboration: Christina teamed with the indie band A Great Big World on the song
Miley has shown herself adept at upping the ante in an especially memorable year that's included some brinksmanship, a few totally odd moments and plenty of skin.
Lady Gaga performed her song Do What U Want with R Kelly, who was dressed up as the president, while Gaga played his secretary.
The pair joked about on stage, playing secret lovers, with R Kelly smoking a cigar at his desk.
Gaga stripped down to a silver leotard for the performance, which ended with a piano-led element to the song.
Paying homage: Jennifer Lopez performed a tribute to singer Celia Cruz and got a standing ovation from the audience, including an excited Justin Timberlake
Showstopper: Jennifer Lopez looked stunning as she showed off her figure in a sparkling leotard
Wowing the crowds: J-Lo certainly looked years younger that her 44-years as she took to the stage
Walking on air: J-Lo gave an energetic performance, and was no doubt cheered on by ex-husband Marc Anthony who was in attendance
WINNERS LIST - 2013 AMERICAN MUSIC AWARDS
Up and coming: Ariana Grande won Kohl's New Artist of the Year award at the event
Favorite Male Artist, Pop/Rock
Justin Timberlake
Favorite Female Artist, Soul/R&B
Rihanna
Favorite Album, Country
Taylor Swift/Red
Favorite Album, Rap/Hip-Hop
Macklemore & Ryan Lewis/The Heist
Favorite Artist, Alternative Rock
Imagine Dragons
Favorite Artist, Latin
Marc Anthony
Favorite Album, Pop/Rock
One Direction/Take Me Home
New Artist of the Year
Ariana Grande
Favorite Male Artist, Soul/R&B
Justin Timberlake
Favorite Female Artist, Country
Taylor Swift
Single of the Year
"Cruise" by Florida Georgia Line, featuring Nelly
Beyond a joke: Justin collects yet more awards for his music
Favorite Album, Soul/R&B
Justin Timberlake/The 20/20 Experience
Favorite Artist, Electronic Dance Music
Avicii
Favorite Male Artist, Country
Luke Bryan
Favorite Band, Duo or Group, Pop/Rock
One Direction
Artist of the Year
Taylor Swift
Favorite Female Artist, Pop or Rock
Taylor Swift
Favorite Band, Duo or Group, Country
Macklemore & Ryan Lewis
Favorite Artist, Adult Contemporary
Maroon 5
Favorite Artist, Contemporary Inspirational
Matthew West
Top Soundtrack
Pitch Perfect