Kerber in position to end Serena Williams's long reign as world number one after reaching last 8.
Lucas Pouille crowned a glorious French charge at the US Open on Sunday by ousting 14-times Grand Slam singles winner Rafa Nadal in a five-set thriller.
The 22-year-old Pouille, seeded 24th, won a deciding tiebreak 8-6 to complete a 6-1, 2-6, 6-4, 3-6, 7-6(6) marathon victory and join compatriots Jo-Wilfried Tsonga and Gael Monfils into the last eight at Flushing Meadows.
"I couldn't dream better than this," said Pouille.
Tenth seed Monfils motored into the quarters with a 6-3, 6-2, 6-3 dismissal of Marcos Baghdatis of Cyprus to launch the French advance at the year's last Grand Slam championship.
Ninth seed Tsonga followed Monfils's lead and booked his quarter-finals berth 6-3, 6-3, 6-7(7), 6-2 over American 26th seed Jack Sock.
Playing his third consecutive five-set match, Pouille, still looking for his first ATP Tour title, showed that his quarter-final advance earlier this season at Wimbledon was no fluke.
After taking a two sets to one lead in the fourth-round match against fourth-seeded Nadal, Pouille slumped in the fourth set and was down an early break in the fifth but brought the match back on serve at 4-4.
In the climactic tiebreaker, Nadal fought off Pouille's triple match point at 6-3, but the Frenchman won the final two points, the last coming on a blistering forehand winner.
"He's young. He's a player that has all the shots. He's a potential top 10," Nadal said of Pouille.
songa advanced to a clash against either world number one Novak Djokovic or unseeded Briton Kyle Edmund.
Pouille will next face compatriot Monfils, who has won 18 of his last 20 matches, winning the biggest ATP World Tour title of his career in Washington during that stretch.
"He's in very good form. He has won so many matches for the last two months," Pouille said about Monfils.
"But I'm playing well. I have good feelings on the court, so we'll see."
Meanwhile, Angelique Kerber won a battle of Grand Slam champions when the second seed powered her way into the quarter-finals on Sunday with a 6-3, 7-5 win over Petra Kvitova.
By reaching the last eight Kerber has put herself in position to end Serena Williams's long reign as world number one.
Williams, bidding for a record seventh US Open title, will now need to reach the final to have a chance of retaining top spot.
The fourth-round match had a definite Grand Slam pedigree to it with Kerber, the Australian Open champion, going against twice Wimbledon champion Kvitova but failed to deliver any major excitement.
Kerber was in command from the start, winning all the big points on way to taking the opening set.
Kvitova, the Rio Olympic bronze medallist, offered more resistance in the second before meekly surrendering with a double fault on match point to gift Kerber a place in the quarter-finals.
Kerber's victory set up an intriguing last eight clash with Italy's Roberta Vinci, last year's surprise runner-up advancing with a 7-6(5), 6-2 win over Ukraine's Lesia Tsurenko.