UPDATE 1-Soccer-Messi strikes to help Barcelona reach final

(Adds Barcelona result, details, byline)

By Iain Rogers

MADRID, March 4 (Reuters) - Lionel Messi struck late to help Barcelona seal a place in the King's Cup final on Wednesday, a 1-1 draw at Real Mallorca completing a 3-1 aggregate victory for the Primera Liga leaders.

Barcelona will play Athletic Bilbao in the May 13 final in Valencia after the Basque club beat Sevilla 3-0 at home to overturn a 2-1 defeat from last month's first leg.

Barca have run into a miserable patch of form since they beat Mallorca 2-0 in the first leg at the Nou Camp and the latest result means they are without a win in five matches in all competitions.

They rode their luck on Wednesday in a match that saw both teams reduced to 10 men.

Gonzalo Castro gave the islanders the lead with a powerful drive that flew into the top left corner at the end of the first half.

Barca goalkeeper Jose Manuel Pinto saved Jose Luis Marti's weak penalty early in the second half, awarded after defender Martin Caceres felled Castro and earned himself a straight red card.

Mallorca lost defender Josemi to a second yellow card in the 65th minute for bringing down Messi.