10/06/2014 11:48 EDT | Updated 12/06/2014 05:59 EST

US Open champion Marin Cilic loses to Ivo Karlovic in 1st round of Shanghai Masters

SHANGHAI - U.S. Open champion Marin Cilic was eliminated in the first round of the Shanghai Masters, losing to Ivo Karlovic 7-5, 2-6, 7-6 (2) Monday.

Karlovic had 20 aces and won 85 per cent of points on his first serve to prevent Cilic from securing his spot at the ATP finals in London.

Cilic is in the sixth spot for the eight-man field, with several players not far behind as the season winds down.

Also, John Isner of the United States hit 22 aces and saved six of eight break points to beat Pablo Andujar of Spain 7-6 (5), 1-6, 6-3, Yen-Hsun Lu of Taiwan beat Marcel Granollers of Spain 6-3, 6-7 (5), 6-2, and qualifier Malek Jaziri of Tunisia defeated Donald Young of the United States 7-5, 6-4.