Britain's Alex Bogdanovic got to within two points of causing a major upset before losing to world number five Andy Roddick at the Artois Championships.
Bogdanovic is currently ranked 117 in the world
Bogdanovic, 23, was two points from victory in the second set tie-break when Roddick made a successful appeal to Hawk-Eye over a line call.
The American went on to take the tie-break and eventually came through 4-6 7-6 (7-5) 6-4.
Second seed Roddick will face Croatia's Marin Cilic in the quarter-finals.
"It was a tough one," Bogdanovic told BBC Sport. "I played quite a loose game in the third set, he took advantage of it and that was it. His serve was really big.
"Every time his first serve was over 130mph and I couldn't get it back. That was the key - he served so big.
Legitimately he should be top 50 by the end of 2007, that's a very realistic goal for him
"I had a chance in the tie break but he played so well and deserved to win."
He added: "It was definitely the best performance of my career. I played a great match.
"Matches like this are really going to help me get to the top. Andy said to me afterwards 'great stuff, if you keep going like this you are going to get up there pretty soon.'"
Roddick admitted that the overrule in the tie-break that saved him from facing a match point had been crucial.
"I've been a big supporter of Hawk-Eye and that's the reason why - needless to say I'd have been a little perturbed if they'd got that wrong," said the American.
And asked if he had been surprised by the Briton's performance, Roddick said: "If I'm being honest, yes.
"He's been around a couple of years now and I know he's been working with Peter Lundgren and it's night and day from what we've seen before."
Roddick added: "If he can play close to that consistently, Britain will have another top 40 player on their hands.
"Legitimately he should be top 50 by the end of 2007, that's a very realistic goal for him. Then he can take it from there.
"His serve is not huge but he hits the spots well. Today he didn't make a lot of errors. He was taking the first ball and hitting it clean.
"Mentally he stayed in the match and didn't play himself out of it all. The challenge is to play like that on a weekly basis, not just in one tournament or one match."
In other matches, third seed Fernando Gonzalez made the quarter-finals with a 6-2 7-5 win over Robby Ginepri, and Marin Cilic beat Jo-Wilfried Tsonga 4-6 6-3 6-2.
Seventh seed Dmitry Tursunov beat Paul-Henri Mathieu 7-6 (7-3) 3-6 6-3.
Russian Marat Safin went out after playing twice in one day, losing 7-6 (7-3) 7-6 (7-4) to Ivo Karlovic.
Safin had earlier polished off his rain-hit match against Sebastien Grosjean 3-6 6-4 6-4, winning six straight points to complete a match held overnight.