Zac Efron made a surprise appearance at the semi-finals of "Dancing with the Stars" to support his brother Dylan Efron, who performed a Tango and a Cha Cha, scoring 27 and 28 out of 30 respectively.Judges Carrie Ann Inaba and Derek Hough praised Dylan's performances despite a minor footwork mix-up, while Zac urged viewers to vote for Dylan via Instagram.Daniella Karagach addressed rumors of tension with Dylan after a viral video, explaining it was an embarrassing moment related to adjusting her outfit, and the pair are set to compete in the finale along with four other couples.