Hamilton reached number 10 in the world in the 1999-00 season
Anthony Hamilton fired three centuries to beat world champion Neil Robertson 5-4 in the German Masters first round.
Hamilton failed to qualify for the first three rankings events this season but won four matches to make round one.
Robertson came from 4-2 down to level but Hamilton sealed his progress to the next round with a 116 century.
Elsewhere, seven-time world champion Stephen Hendry beat Judd Trump 5-2, but Nigel Bond, winner of January's Shoot-Out event, lost 5-1 to Mark Selby.
Hendry was hugely relieved to secure his place in the second round given that his place in the elite top-16 is under threat.
"It was a big game for both of us and I think that showed," he said. "I need wins so every match is important but I'm also playing for my own pride too."
Ronnie's very likeable when he wants to be but he should start considering his future in the game and his responsibilities to it
World Snooker chairman Barry Hearn
In the all-Northern Ireland encounter, Mark Allen, who reached the semi-finals of the Masters at Wembley last month, beating Ronnie O'Sullivan and Robertson along the way, lost 5-3 to Joe Swail, a World Championship semi-finalist in 2000 and 2001.
And the ever-obdurate Peter Ebdon shared the first four frames with Andrew Higginson in more than two hours before recording a 5-3 win.
Recent Masters champion Ding Junhui beat Matthew Stevens 5-1, while former world champions Graeme Dott and Shaun Murphy also triumphed on Thursday.
Three-time world champion Ronnie O'Sullivan, winner of the German Masters in its original format in 1997, cited medical reasons for pulling out of playing in Berlin, handing Dominic Dale a walkover but left World Snooker chairman Barry Hearn less than impressed.
"An awful lot of people are going to be disappointed he's not there," Hearn said about O'Sullivan, who also withdrew from the Shanghai Masters, where he was defending champion, and 10 of the 12 new minor-ranking events.
"It's his face on all the posters in Germany. It's a very important tournament for us as we try to develop the European market. This can't go on. Ronnie's very likeable when he wants to be but he should start considering his future in the game and his responsibilities to it."
'The Rocket' has seen his ranking slip to number nine in the world.
World number one John Higgins and Mark Williams, whose ranking has risen to number three, are in action in their first-round clashes on Friday.
The German Masters is one of seven ranking events on the revamped 2010/2011 snooker calendar with Hearn continuing his drive to globalise the sport outside the UK.
The campaign's first ranking event was in Shanghai, followed by the World Open in Glasgow and the UK Championship in Telford.
The Welsh Open and China Open in Beijing are coming up with the season wrapping up at the Crucible with the World Championship in May.
Aussie Robertson clinches world snooker title (UK users only)