Britain's Alex Bogdanovic came close to causing a major upset before eventually losing to world number five Andy Roddick at the Artois Championships.

The 23-year-old, playing well above his 117th place in the ATP rankings, 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 win the tie-break and eventually triumphed 4-6 7-6 (7-5) 6-4.

"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 Roddick, who will face Croatia's Marin Cilic in the quarter-finals.

"It was a tough one," Bogdanovic said. "I played really well but played a loose game in the third, he took advantage and that was it. He served really big and that was the key, I just couldn't get it back. I had a little chance in the tie-break but he deserved to win."

Earlier Bogdanovic had stunned the second seed by clinching the opening set. Apart from two blistering service games from his American opponent who looked a little out of sorts, Bogdanovic defied his heavy underdog status to control the set.

He made an impressive start and secured break point in the third game with a perfectly-placed backhand leaving Roddick stranded.

Roddick was strangely subdued for long spells and a series of unforced errors were followed by anguished glances to his coach Jimmy Connors.

Bogdanovic's reputation for crumbling under pressure could have come to the fore again at 30-30 when he was serving for the set. But he then sent down two skidding serves that were enough to move the left-hander into the lead.

Roddick was struggling to find any rhythm as his opponent moved him cleverly around the court, but his serve was good enough to keep him in the second set.

It went to a nerve-jangling tie-break and hinged on a crucial challenge by Roddick. His forehand at 5-5 was ruled out but Hawk-Eye showed it had just clipped the line, giving him a set point that he immediately converted.

That was enough to breath new life into Roddick, who served 22 aces, and he finally stepped up the tempo, breaking in the seventh game of the final set and serving out the match.

Asked if he had been surprised by Bogdanovic, 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. If he keeps up that pace it will be exciting for the fans in Britain."

"I thought Alex played a good match, he kept the pressure on from the first ball and I was lucky to get out of there today."