Spanish singing legend Julio Iglesias, 64, has interrupted a concert tour in the Russian city of Yekaterinburg because of a heart problem, reported dpa.
Iglesias started feeling unwell after performing two songs at Tuesday's concert, which was rescheduled for Thursday.
Doctors associated the heart trouble with stress and advised Iglesias to rest.
"I am well, it is the first time this happens to me," Iglesias was quoted as saying.
Iglesias started his Russian tour in Moscow last week. He has some 20 concerts scheduled for the summer in countries including Syria, Romania, Finland, Spain, Portugal, Italy, Belgium and the United States.
Iglesias is one of the world's best-selling singers, with more than 2,600 gold and platinum records to his credit. He has fathered eight children, including singer Enrique Iglesias.