Serena battles through tension-filled U.S. Open fourth round

Serena Williams 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 on Monday.

The 23-times Grand Slam winner came up short in the second set tie-break, 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 has 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-times 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.”