NEW YORK, NY (Reuters) – Serena Williams NYSE:WMB) advanced to the U.S. Open quarter-finals after a gritty, tension-soaked 6-3, 6-7(6), 6-3 win over Greece’s Maria Sakkari yesterday.

The 23-time Grand Slam winner came up short in the second-set tiebreak, with her power serve abandoning her when she needed it most.

Sakkari carried the momentum into the third set as she started the decider with a break.

But the 38-year-old American once again showed the battling instincts that have made her one of the all-time greats. She broke back to level for 2-2 as Sakkari’s forehand started to misfire.

The six-time Flushing Meadows champion marked her 100th win on Arthur Ashe Stadium with a roar that could be heard all around the grounds.

“I just kept fighting,” said Williams, who lost to Sakkari two weeks ago in the Western & Southern Open.

“She was doing so well; she was being so aggressive.

“I knew I needed to do the same thing.”