As Yatsenyuk gave a speech Friday defending his government's record, Oleh Barna, a member of parliament from President Petro Poroshenko's political bloc, presented him with a bouquet of roses, grabbed him by the chest and attempted to carry him from the rostrum.
When Yatsenyuk, still clutching the roses, resisted, Barna changed grips, seizing the prime minister by the groin for better leverage. A half-dozen of Yatsenyuk's supporters quickly fell on Barna in a flurry of punches, and Yatsenyuk was freed. The brawl was on.
It was not immediately clear why Barna, who is regularly involved in brawls in the Rada, gave Yatsenyuk the roses. But it was immediately clear that the fight had captured widespread attention, and the scene quickly reappeared on social networks with soundtracks like "Get Your Freak On" by Missy Elliot.
Photoshopped scenes with Barna clutching Yatsenyuk by the groin soon appeared.
The fight illustrated how political parties that share similar, pro-Western ideologies are still at loggerheads in Ukraine because of personal enmities between their leaders. Western diplomats have said they are growing tired of the slow pace of reform and continuing corruption, and Biden's visit to Kiev was seen as a vehicle to deliver that message.
Biden, addressing the parliament in lofty tones Tuesday, recalled Thomas Paine's quote: "These are the times that try men's souls."
"This is your moment," Biden said. "This is your responsibility. Each of you -- if you’ll forgive me for speaking to you this way in your body -- each of you has an obligation to seize the opportunity that the sacrifices made in the Maidan."
"Just like Biden said," tweeted Alex Ryabchyn, a member of parliament, along with a picture of the brawl, Friday.