Raducanu missed last year’s Wimbledon after having surgery on both of her wrists and has needed to be patient on her return to the WTA Tour this year.
Difficult decisions have also needed to be made.
On Saturday, she made the “very difficult” move to pull out of her mixed doubles partnership with Andy Murray – whose Wimbledon career is now over – because of stiffness in her wrist.
Raducanu has been cautious in her scheduling this year and opted to miss the clay-court French Open in order to ensure she was in peak condition for the British grass-court season.
The move has been fully justified.
After encouraging runs in Nottingham and Eastbourne, Raducanu has played some of her best tennis this week since winning the US Open.
“Honestly, I’m just obsessed with tennis right now,” said Raducanu.
“It’s all I want to do and all I want to think about.”
Raducanu needed to come through a first-set tie-break against Mexican lucky loser Renata Zarazua in round one, but has dropped just 11 games since after commanding wins over Belgium’s Elise Mertens and Greek ninth seed Maria Sakkari.
The excitement among the British fans at the All England Club has been further fuelled by Raducanu’s section of the draw opening up.
If the former British number one beats Sun, another unseeded opponent – Spanish former world number two Paula Badosa or Croatia’s Donna Vekic – waits in the quarter-finals.
“I just love playing on the big stages so much,” said Raducanu.
“It’s my favourite thing in the world, it’s the reason I play tennis, to play on these big courts and these big matches.
“It’s really special, you don’t get these opportunities often in life.
“When I look back later in my career, when I get much older and have retired, I want to be able to tell myself I savoured every moment.
“So I play each point as if it’s my last.”