Bayern Munich are on course to win their opening Bundesliga fixture of the season after Mehdi Benatia headed the champions in front against Hamburger SV.
The Bavarians were almost behind within four minutes as Lewis Holtby linked up with Sven Schipplock before the ex-Tottenham Hotspur midfielder fired his volley straight at Manuel Neuer.
Minutes later, Bayern nearly took the lead themselves after a chipped pass from David Alaba was met by a well-timed run from Arjen Robben, but the Dutchman sent his effort wide of the target.
The champions looked to increase the tempo of their passing game and came close again midway through the half, as Philipp Lahm delivered a cross into the path of Robert Lewandowski, only for the Polish striker to head over the bar.
However, Pep Guardiola's men finally broke through on 27 minutes as a pinpoint cross from Alonso's free kick allowed Benatia to rise at the far post and head beyond a helpless Rene Adler.
Bayern were almost 2-0 up as Alaba raced down the flank and found Thomas Muller in the centre, but the German dragged his shot wide.
