Nhat Nguyen is through to the last-16 at the Badminton World Championships.
The Dubliner beat English no.1 Toby Penty 21-17, 23-21 in Huelva on Tuesday afternoon.
Nguyen opened up his second of the men's singles draw by downing seventh seed Jonatan Christie in the first round.
His performance is all the more remarkable, given his recovery from serious illness.
"Leading into this I had less than one week practice," Nguyen revealed afterwards, "I had pneumonia for nearly four weeks.
"So one week before this I wasn’t even sure if I’d be participating."
Nguyen added, "That’s why towards the end my condition wasn’t really so good.
"It was a little bit tense because I didn’t know if I’d last a third game. The second game was important for me.
"But I fought with everything I had. I’m lucky it was just enough. I was cramping and had a weird sensation on court. I was a bit lucky towards the end.
“Pneumonia’s set me back, definitely. I’m struggling to breathe. My legs feel it. I have a bad record against Toby, so this win was quite big for me.
"I struggled before, so I’m happy I could overcome him. This was actually an important win.”
Next up for the Olympian is a meeting with China's Zhao Ju Peng for a place in the quarter-finals. Nguyen is ranked six places above Zhao in the latest world rankings.
The world no.42 comfortably beat Koki Watanabe of Japan 21-11, 21-5.