Defending US Open champion Marin Cilic has advanced to the second round of the tournament by beating Guido Pella in straight sets.

The 26-year-old made a strong start to the defence of his title by winning 6-3 7-6[3] 7-6[3] in the first-round encounter.

Cilic broke his Argentine opponent in the second game of the opening set, before holding his serve to assert his early dominance.

It was a far more even second set, as both players held their serves, with Cilic eventually triumphing 7-3 in the tie-break.

Pella reacted well to that blow and broke Cilic early on in the third set, before he lost his serve in the eighth game. The two players then held serve as the set headed into another tie-break.

Once again it was Cilic who held his nerve, as he broke Pella five times on the way to another 7-3 win, to keep his hopes of a second straight title at Flushing Meadows alive.