Bayern's 69 million euros summer spending spree was rewarded after just 14 minutes as Klose, a 12 million euro signing from Werder Bremen, drew the goalkeeper for 11-million euro man Toni to knock the ball into an empty net.

Despite having injured knee ligaments in a pre-season game, Toni, 30, was a constant threat to Hansa on his debut, but Bayern coach Ottmar Hitzfeld later admitted he had gambled on the Italian's fitness.

Klose, the top-scorer at last year's World Cup, showed his class to put Bayern 2-0 ahead as he followed up defender Philipp Lahm's shot to slot home on 66 minutes, before adding his second on 84 minutes, heading home Lahm's cross.

"I am glad that the risk to play Luca Toni paid off. I think for a lot of fans it was worth the entrance fee alone to see him play," said Hitzfeld.

"We fulfilled our duty, the team put Rostock under pressure from the start and played well, we deserved our 1-0 lead at the break.

"But we gave Rostock too many opportunities to counter-attack, because we were badly organised at the back and we must improve on that."

After suffering their worst season for 11 years to finish fourth last season and miss out on a Champions League place, Bayern's agressive spending over the summer looks to be a good investment as a host of their new stars shone.

As well as Italian World Cup winner Toni and Klose, French midfielder Franck Ribery was in superb form, while German defender Marcell Jansen was also solid in defence and quick in attack as Hansa rarely troubled Bayern.

Last season's third place finishers Werder Bremen squandered a 2-0 lead at VfL Bochum to settle for a draw. Brazilian Diego netted on 39 minutes before summer signing Boubacar Sanogo scored in first-half injury time.

But Bochum got themselves level as strikers Stanislav Sestak of Slovakia and Dane Tommy Bechmann both scored within four minutes of the break to make it 2-2.

Hamburg started the season with a 1-0 win over Hanover as Namibian international Collin Benjamin hit the back of the net after 23 minutes, which proved enough to seal the points.

Eintracht Frankfurt also opened their season with a 1-0 win over Hertha Berlin after Greek striker Ioannis Amanatidis struck with a header on 31 minutes.

Having both been dumped out of the German Cup first round the previous week, there was nothing to seperate Bayer Leverkusen and Energie Cottbus who drew 0-0.

Arminia Bielefeld enjoyed a 3-1 win at VfL Wolfsburg with goals from Polish striker Artur Wichniarek, fellow forward Christian Eigler and defender Oliver Kirch.

On Friday night, last season's runners-up Schalke 04 came away from defending champions VfB Stuttgart with a precious point after a 2-2 draw.

Schalke's Gerorgian midfielder Levan Kobiashvili slotted the first goal of the new season but Stuttgart's Sami Khedira scored before Mexican midfielder Pavel Pardo converted a penalty in the second-half to give the champions the lead.

But Schalke's teenage super sub Ivan Rakitic scored just seven minutes after coming on to seal the draw.

On Sunday, German Cup winners Nuremberg host newly-promoted Karlsruhe, while Borussia Dortmund are at home to new boys Duisburg.