Barack Obama, who spent the best part of last year fighting a gruelling battle for another term in the White House, had a bigger fight on his hands hours after being sworn into office on Monday - taking on singer Usher in a 'Gangnam Style' dance off.
The President and his wife Michelle threw a spectacular after-party at the White House after attending two glitzy events celebrating his inauguration.
Hundreds of high-profile guests attended the exclusive bash which finally came to a close at 3 am, the Daily Mail reported.
Celebrities shared photographs of the First Lady, still wearing her glamorous red Jason Wu gown, dancing to Beyonce's hit 'Single Ladies', while her husband hugged and chatted with guests, his tie undone after a busy day.
According to India Benet, the teenage daughter of singer Eric Benet, late into the night, the current US President relaxed even more.
"Getting down on the dancefloor with the COOLEST crowd of people ever!!!" the Daily Mail quoted her writing alongside a picture showing her grinning at the camera in the White House.
"After this, the President and Usher had a dance off to Gangnam style!!" she wrote.
Obama had previously revealed that he performs the dance around his home to tease his daughters, who hate the dance. His wife added that the moves were "a little embarrassing".
But his guests didn't seem to mind, and the celebrities took to Twitter to enthuse about the party and share photographs of the night.
"I don't even know what to say. It's 3:15am and I just teared up seeing our president getting down at the white house," model Chrissy Teigen tweeted.
Kelly Clarkson, who had performed at Obama's swearing-in ceremony that morning, tweeted just before midnight "Just partied at the White House. I kid you not, Michelle Obama stood up and got the party started...seriously cool First Lady."
"Just left the White House," Katy Perry wrote at 3 a.m.
"All other parties from here on our will be judged unless they take place at the White House," she wrote.
Ashley Judd, who hitched a ride with an off-duty Secret Service agent to get to the White House, described called the celebration as "an amazingly joyful house party. We had such a magical night."
Other guests included Alicia Keys and her husband music producer Swizz Beatz. Miss Benet tweeted that Bill Clinton also attended the event.
The Chicago Sun Times added that Sasha and Malia Obama joined their parents on the dancefloor at one point, and that when 'Soul Train' played, Obama led the dancing line.
The Obamas also threw an after-party after the President's first inauguration in 2009 - although it was a much quieter affair. After the Obamas left their final party at 12.45 a.m., Oprah Winfrey was among the select guests invited back to the White House to sip on champagne.
This year around 2,000 guests enjoyed an open bar, sliders and Chicago dogs at the invite-only event, which was part-hosted by actress Eva Longoria.
Will.I.Am and actresses Sophia Bush and Malin Ackerman were reportedly seen dancing beside White House staffers at the 'Midnight Underground, a Chicago-style after-hours' party, which finally finished around 3 a.m.
By contrast, President and Mrs Obama looked fresh-faced as they attended the Presidential Inaugural Prayer Service at the National Cathedral with the Bidens, just hours after the party finished. Around 2,200 people streamed into the cathedral for the service. (ANI)