As photographer Stefen Chow took a portrait shot of Chinese artist and dissident Ai Weiwei, the latter raised his iPhone to take a snap of his own.
But it was Mr Chow's picture that went on to win an award for staged portrait in last year's World Press Photo contest. The picture is now on display at Raffles Hotel - along with 153 other photos from 54 photographers - until March 30.
Dubbed "the Oscars of photojournalism", the contest received about 103,500 photo submissions from more than 5,000 photographers.
Swedish photographer Paul Hansen's photo of two dead children being carried through Gaza in the wake of a missile attack on the Palestinian city clinched 2013's photo of the year award.
Mr Chow, a Singapore permanent resident, said his winning portrait was taken at a "very tense" time after Ai Weiwei had been released from house arrest.
"I wanted to create an image that was timeless and sombre," Mr Chow said. "If he was taken away the next day, I wanted this to be the photo that was remembered."
Singapore is the last stop for the 2013 exhibition, which has visited 45 countries so far. It is only the exhibition's third visit here in its 58-year history, its last being in 2006. The Straits Times is its official media partner.
Said Straits Times editor Warren Fernandez: "These award winning pictures capture the human emotions involved in crisis situations, sports events and everyday life. They tell powerful stories visually. They help convey the drama of news events, as good journalism tries to do, whether in print or online."
The exhibition was officially opened last night by Acting Minister for Culture, Community and Youth Lawrence Wong.
"Good photos transcend superficial coverage," Mr Wong said. "Good photojournalists have... the intuition in seizing the decisive moment and the sensitivity to convey a compelling story."
Admission to the exhibition is free and visitors can download an audio app for a virtual tour of the photographs on display.
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