BERLIN (Reuters) - World number two Ana Ivanovic suffered a surprise 6-2 7-5 defeat by Elena Dementieva in the semi-finals of the German Open on Saturday.

The 20-year-old Serbian made far too many unforced errors and was broken five times by the Russian seventh seed.

Dementieva, ranked nine in the world, will play compatriot Dinara Safina in Sunday's final after the 13th seed posted a 6-4 6-1 win over unseeded Belarussian teenager Victoria Azarenka earlier on Saturday.

(Editing by Clare Lovell)