WHAT HAPPENED: Venus Williams overcame an inconsistent serving performance to blow past a stunned Carla Suárez Navarro to make the second week of the US Open for the 12th time in her career.

As with her other matches over the first six days of the tournament, it wasn’t a vintage effort. But it had all the hallmarks of what has made Venus so successful: fight, grit and an extra gear when she needed it most.

After dropping the second set and sharing a split of the opening two games in the third, Venus turned up the pressure on Suárez Navarro with a barrage of penetrating strokes, blasting through to win the final six games in a row.

play video Cognitive Highlight: Venus Williams - Round 4

The two-time US Open champion captured the first set behind three breaks of serve, masking the fact that she was missing every other first serve, struggling with her ball toss and losing two-third of her second-serve points when the Spaniard was able to get the first strike in from the back of the court.

Suárez Navarro broke twice in three chances to establish a double break and a 3-0 lead at the start of the second set, and she sent the match to a decider when Venus hit a backhand long in a game she led 30-0 and 40-15.

But if Suárez Navarro had the momentum, it didn’t last long. Venus broke in the third and fifth games of the third set as she took full control of the match to leave little doubt in the final outcome. A third consecutive hold made it 5-1, and a monstrous cross-court forehand return three points later gave the American triple match point.

The 28-year-old Barcelona native saved the first, but an exquisite half-volley pickup at the net put a bow on a perfect final-set performance and brought out a wide smile and her trademark twirl. 

WHAT IT MEANS: Venus is into the quarterfinals of the final major of the year for the second time in three years after failing to make it past the third round in four consecutive trips to New York between 2011 and 2014.

The run to the second week continues an outstanding year for the 37-year-old, who reached the final of the Australian Open and Wimbledon earlier this season.

The last time Venus made three quarterfinals in the same year was 2010, also the last of eight semifinals she has appeared in in Flushing Meadows.

She will now play the winner of the first evening session in Arthur Ashe Stadium on Sunday between No. 3 seed and Wimbledon champion Garbiñe Muguruza and No. 13 seed Petra Kvitova. Venus has a 3-2 lead over Muguruza, but dropped their last two meetings, in the Wimbledon final and the Rome quarterfinal. Against Kvitova, Venus is 1-5, her lone win coming in Miami in 2012.

For Suárez Navarro, she was one win from matching her best Grand Slam performance. She has reached the quarterfinals of five majors, including the US Open once before in 2013.

MATCH POINT: Venus can turn up the intensity when she needs it the most, finding an extra burst of energy to see her over the finish line. Is that going to be enough against better opponents as the tournament enters its final few days after Labor Day?