Sharapova, who is currently ranked 146^th in the world, lost the fourth-round match 7-5, 4-6, 2-6 at Flushing Meadows in New York City.

"It's been a really great ride in the last week," the 30-year-old, who was given a wildcard into the main draw, was quoted as saying by BBC Sport.

"I can take a lot from this week.

"It's great to get that major out of the way.

"It was an incredible opportunity."

Awaiting Sevastova in the quarter-finals is the United States’ Sloane Stephens, who beat Germany’s Julia Goerges 6-3, 3-6, 6-1.

Also through to the last eight is 13^th seed Petra Kvitová of Czech Republic thanks to a straight-sets victory over reigning Wimbledon champion Garbiñe Muguruza of Spain.

Kvitová, who returned to action in May after an attacker at her home in December stabbed her in the hand, fought back from 1-4 down in the first set to defeat the third seed 7-6, 6-3.

Next up for the 27-year-old is Venus Williams after the American overcame Spain’s Carla Suárez Navarro 6-3, 3-6, 6-1.

In the men’s singles draw, 12^th seed Pablo Carreño Busta  of Spain beat Canadian qualifier Denis Shapovalov 7-6, 7-6, 7-6 to reach the US Open quarter-finals for the first time.

The world number 19, who is the highest-ranked player left in the bottom half of the draw, will next face Diego Schwartzman after the Argentinean defeated France’s Lucas Pouille 7-6, 7-5, 2-6, 6-2.

The evening session saw 17^th seed Sam Querrey of the US cruise to a 6-2, 6-2, 6-1 win over Germany's Mischa Zverev.

Victory for Querrey means he is the first American to reach the US Open quarter-finals since 2011, when John Isner and Andy Roddick both made it to that stage. 

Standing between him and a place in the penultimate round is 28^th-seeded South African Kevin Anderson, a 6-4, 6-3, 6-7, 6-4 victor at the expense of Italy's Paolo Lorenzi.

By reaching the quarter-finals, Anderson has equalled his best-ever Grand Slam performance.

He progressed to the last eight of the 2015 US Open before losing to Switzerland’s Stan Wawrinka.