Marin Cilic needs a superhuman effort over the next fortnight to stay in contention for the ATP year-end finals after losing the Austria Tennis Trophy 6-4 6-3 to Jurgen Melzer in Vienna on Sunday.

The Croatian stands a provisional 13th and now comes under the cosh from Monday in Basel and the subsequent Paris Masters if he's to win a first-ever spot in the eight-man World Tour Finals in London from November 22.

"I really have to produce something for the rest of the season," said the 13th-ranked Cilic, winner of titles in Chennai and Zagreb who has now lost two finals in four weeks after Beijing last month.

"I have a lot of things to improve in my game, just about everything. I also need to add some extra kilos.

"These last two weeks will be very important for me. I really want to do everything to try and get to London. I've showed this season that I have the game to face the big guys - now I have to prove that."

Melzer thrilled his home nation in the 90-minute victory, becoming the first Austrian to lift the Vienna trophy since Horst Skoff in 1988, who beat Thomas Muster.

Muster, the former king of clay, was the last Austrian into the final at the Stadthalle, where he lost the 1995 final to Belgian Filip Dewulf.

"This is unbelievable, to beat Cilic for this title is really a great accomplishment. I'm really happy," said the winner, who was winning his second career title after Bucharest three years ago.

"I'm really just so pleased to be able to win it at home. I'm really happy. This is the best thing to happen to me in my career.