By Adrianna Outlaw
© Mark Peterson/Corleve

(January 22,2011) Tennis' marathon man came up a step short at the finish line today. Marin Cilic converted the only service break of the last three sets to edge John Isner, 4-6, 6-2, 6-7(5), 7-6(2), 9-7 to reach the Australian Open fourth round.

The 20th-seeded Isner delivered 26 aces, but converted just one of 11 break-point chances against 2010 semifinalist Cilic. Isner scored his lone service break in the first set and was 0 for 6 on break-poin chances over the final four sets.

The 15th-seeded Cilic could face 2009 champion Rafael Nadal for a quarterfinal spot. Cilic hit 22 aces. The Croatian committed two double faults to face a break point at 2-all in the final set, but erased the break point with a stinging forehand.

Isner's loss leaves Andy Roddick as the only American man still standing in Melbourne. Four-time semifinalist Roddick will take on 19th-seeded Swiss Stanislas Wawrinka with the winner possibly playing defending champion Roger Federer for a place in the final four.