Canadian teenager Leylah Fernandez continued her remarkable US Open run as she beat 2016 champion Angelique Kerber to advance to the quarter-finals.

On the eve of her 19th birthday, Fernandez backed up her win over Naomi Osaka with a 4-6 7-6 (7-5) 6-2 victory over Germany's Kerber.

She battled back from a 4-2 deficit in the second set to force a tie-break and barely let up from then on.

Fernandez will face fifth seed Elina Svitolina for a semi-final spot.

Fernandez doubled over as her victory was confirmed before she was given a standing ovation by a full crowd on Louis Armstrong Stadium.

"I was just glad I was having fun on the court," Fernandez said.

"I have been working hard since the day I started playing tennis and the day I set my mind to being a professional.

"I expected that one day my tennis game is going to come through and that I'm going to be on the big stage in front of a big crowd and getting the wins."

The kids are alright
Fernandez is one of three teenagers to have broken through at the US Open, registering victories over four-time Slam champion Osaka and three-time winner Kerber.

Fellow 18-year-olds Emma Raducanu of Britain and Spain's Carlos Alcaraz have also advanced to the fourth round, with Alcaraz taking out third seed Stefanos Tsitsipas earlier in the week.

Born in Montreal, Fernandez was cut from the provincial development program at a young age, with the family moving to Florida to build her and her sister's careers.

Her father Jorge, a former soccer player who turned professional at 13, learned tennis in order to coach his daughter.

It paid off, with Fernandez winning the 2019 French Open girls singles title and breaking into the top 100 the next year.

Despite being the youngest player in the main draw, she won her first WTA title in Monterrey, Mexico in March, and did not drop a set throughout the week.

She showed her fearlessness against Kerber, hitting 45 winners, and showing total composure to battle her way into the last eight.

Fernandez battles back

Fernandez did well to put her first-set disappointment behind her, where she let an early break slip.

She served for a 5-2 lead but was broken by an increasingly belligerent Kerber, with the Canadian winning just two more points in the rest of the set.

Former world number one Kerber used her forehand to great effect in the second set but she too let a break go, with Fernandez hitting a scorching winner out of the air to force it to 4-4.

Kerber was forced to save a set point en route to forcing a tie-break, but Fernandez raced to a 5-1 leave, with Kerber giving her support box a sarcastic thumbs-up at the change of ends.

After Kerber sent a volley long to hand over the set, Fernandez gestured to the crowd to more noise, with most jumping out of their seats to give her an ovation.

Known as one of the best defenders in the women's game, Kerber's energy started to fade under the relentless pressure from Fernandez.

Fernandez will now face Svitolina, who is on a nine-match unbeaten streak after her 6-3 6-3 victory over Simona Halep.

Svitolina is the second highest-ranked player left in the competition after the exits of world number one Ashleigh Barty and third seed Osaka.

Second seed Aryna Sabalenka overcame 10 double faults to beat her former doubles partner Elise Mertens 6-4 6-1.

The Belarusian will play French Open champion Barbora Krejcikova after the Czech defeated Spain's former world number one Garbine Muguruza 6-3 7-6 (7-4) in the night session on Arthur Ashe.