FRANKFURT, May 6 (Reuters) - Bayern Munich won the German title for the 20th time and completed an historic "double double" when closest rivals Hamburg SV were beaten 4-2 at Hertha Berlin on Saturday.
Bayern could only manage a 1-1 draw at Kaiserslautern but Hamburg's failure to get the win they needed left them six points off the pace with one game left.
Felix Magath's side become the first to successfully defend a Bundesliga and German Cup double, after beating Eintracht Frankfurt 1-0 in the Cup final in Berlin last Saturday.
"That's four titles in two years now," Magath told reporters. "I don't think we've made too many big mistakes."
Bayern clinched last season's league title with a 4-0 win but their hopes of a similar stroll over the finish line were quickly dashed.
At halftime they trailed to a Halil Altintop goal at Kaiserslautern while Hamburg led 2-1 thanks to Piotr Trochowski and Benjamin Lauth.
But Hertha equalised through Alexander Madlung in the 55th minute and, despite having Andreas Neuendorf sent off four minutes later, they clinched victory through Nico Kovac and Marko Pantelic.
In their match, Bayern grabbed an equaliser through Andreas Ottl in the 68th minute to ease their nerves and with Hamburg being well beaten they were able to start their celebrations on the final whistle.
"It wasn't easy and at halftime it wasn't looking too good," said Bayern keeper Oliver Kahn.
Hamburg's surprise defeat against 10-man Hertha means they are in danger of missing out on second spot and automatic entry to the Champions League.
Third-placed Werder Bremen won 6-0 at home to relegated Cologne to close within a point of Hamburg. Tim Borowski, Miroslav Klose and Ivan Klasnic scored two apiece in the rout.
Second spot will now be decided in a crunch game between the two northern rivals at Hamburg's AOL Arena next Saturday.
Bayern can look forward to a huge celebration in front of 70,000 fans at their Allianz Arena next weekend.
"I'm glad we did it with a week to spare," said Bayern manager Uli Hoeness. "It'll be a nice party next week against Borussia Dortmund."