Bayern Munich started their defence of the league title with a 2-1 win over Wolfsburg at the Allianz Arena on Friday night.
Pep Guardiola gave a debut to 17-year-old Guadino, as Bastian Schweinsteiger missed out through injury, while Robert Lewandowski made his league debut for the German champions.
The first meaningful opening of the first half fell to Lewandowski in the 30th minute, as his poked effort from close range forced Grun into a fine save.
Six minutes later and defending champions went ahead, as Thomas Mueller turned home Arjen Robben's low cross.
Bayern doubled their lead a minute after the halftime break, as Robben played a neat one-two with Lewandowski, before slotting past Grun.
Minutes later and the visitors pulled one back and it was a former Munich striker, Ivica Olic, as he did well to turn Holger Badstuber before curling one into the top corner from the egde of the area.
Lewandowski should have increased Bayern's lead in the 58th minute, as he got beyond the Wolfsburg defence but failed to lob the on-rushing Grun.
Bernard Malanda Adje should have brought Wolfsburg level with 15 minutes to play, as his close range was saved by Manuel Neuer, while managed to place the rebound wide of the marl with the goal at his mercy.
Robben almost increased Bayern's advantage in the closing stages of the game, but his effort from the edge of the area cannoned off the crossbar.