Bieber vomits onstage during concert Singer Justin Bieber performs during Japanese TV event in Tokyo, Japan, on July 11, 2012. 30 (UPI) -- Pop star Justin Bieber twice had to leave the stage after vomiting during the first concert of his "Believe" tour in Arizona, two radio personalities said. Johnjay Van Es and Rich Berra, of the syndicated morning radio show Johnjay and Rich, told KTVK-TV, Glendale, Ariz., Bieber had complained about feeling weak backstage before the concert Saturday. They said he was eating nachos and drinking Gatorade. Bieber managed to finish the show at Jobing.com Arena in Glendale, despite vomiting twice onstage, KTVK reported Sunday. The pop star thanked the fans for their support and even managed to finish an encore, Van Es and Berra said. The next concert on Bieber's 45-city tour is Sunday in Las Vegas at the MGM Grand Garden Arena.