Hewitt ended a run of 15 consecutive defeats by Federer
Roger Federer suffered a rare defeat on grass as he was beaten 3-6 7-6 (7-4) 6-4 by Lleyton Hewitt in the final of the Gerry Weber Open in Halle.
Before Sunday, Federer had been defeated on grass just once since 2003, that coming in the remarkable 2008 Wimbledon final against Rafael Nadal.
At Halle, Federer had won 29 straight matches as he secured five straight titles in Germany from 2004 to 2008.
The six-times Wimbledon champion had not lost a match there since 2002.
Hewitt, a Wimbledon winner in 2002, ended the two hour 20 minute contest with a shot which hit the tape and dropped dead on Federer's side.
The victory for the Australian, at 29 a year older than Federer, ended a run of 15 defeats to the Swiss superstar.
After cruising through the previous four rounds without dropping a single set, Federer - who did not compete at Halle in 2009 - certainly met his match in an eye-catching battle between two former world number ones.
The Swiss started strongly and earned two breaks on Hewitt's first service game and appeared set to make light work of his sixth Halle final, taking the first set 6-3.
But Hewitt broke early in the second set, confirming he was willing to make a fight of it.
Federer broke back immediately and the game followed serve. Hewitt won the tie-break, converting his fourth set point to level the match and becoming the first player to take a set off Federer in Halle since 2006.
The final set belonged to the Australian, who broke again in Federer's first service game and never looked back.
"It's fantastic," said Hewitt who will surely move on to Wimbledon, which starts on 21 June, with renewed confidence.
"Roger is a hell of an opponent and everybody knows how good he is on grass. His record speaks for itself and I just got lucky."