Emma Raducanu believes trying to “let go” of frustration helped her seal a straight-sets victory over Yuan Yue at the Korea Open.

The 21-year-old needed seven match points to clinch a hard-fought 6-4 6-3 victory over the eighth seed to progress to the quarter-finals of the competition.

Raducanu edged in front following a close first set and powered ahead at the start of the second before holding off a comeback from Yuan.

Victory means she will now face number one seed Daria Kasatkina in the final eight.

Speaking about her performance, Raducanu said in her on-court interview: “I think my key to success today is trying to let go of any frustration that happened.

“Closing out the match I had a lot of match points and couldn’t convert. (It was about) just staying focused and breaking in that last game.”

The momentum of the first set shifted when the Briton broke Yuan’s serve to take a 5-4 lead and following a medical timeout, Raducanu then successfully served out the set.

She picked up where she left off, breaking Yuan’s serve in the opening game of the second set.

Raducanu won her sixth straight game of the match to go 3-0 up, but was broken in the fourth game as Yuan pulled one back and the Chinese player looked to pile on the pressure.

A tight battle in the eighth game produced seven deuces before Yuan eventually held serve, but the Briton stopped any chance of a late comeback by wrapping up victory in the following game.

Raducanu was particularly impressive with her serve throughout the match, producing 11 aces including eight during the second set.

Her serves helped her reach a fifth WTA quarter-final this year and she admitted it is something she has been working on.

“If you watch my serve over the past few months, since the clay season it’s gone through a lot of iterations in terms of swing,” Raducanu told the WTA website afterwards.

“In general, if you play a lot of tournaments, things move out of place without you really realising, and then it’s harder to get the natural feeling back.

“We’ve been working hard the last week looking at the swing, and which swing suits me best. It’s been pretty big changes, it’s not like we’re just changing the ball placement.

“Me and my coach decided we were going to take a risk and we were going to tweak things. We know it might not pay off short-term.

“But one thing I do back myself on is I pick things up pretty quickly. In the first match it didn’t transfer yet, but today it definitely did.

“I just have to think bigger-picture. My goals are finishing this season strong but inevitably to set myself up in the best way possible for next year, because next year I really want to hit the ground running.”