Fans were treated to surprise after surprise during Friday night's show at the Rose Bowl in Pasadena, California.
Martin took the mic to tell the 60,000 fans in the stadium, "Over the last few weeks, there's been so much news from so many places that left us feeling powerless and useless."
He continued, "So Sunday, we're planning a show for Mexico City in San Diego ... All of the money from today's concert and Sunday's concert we're going to give to the disaster relief fund."
A spokesperson for the Red Cross tells The Blast that Coldplay's donation will go to the Mexican Red Cross, which will use the funds raised for earthquake relief.
After the announcement, Martin introduced James Corden to provide backup vocals on "Us Against the World."
Corden came back onstage later and everyone sang "Free Fallin'" in tribute to Tom Petty.