Berlin (XINHUA) - Robert Lewandowski's hat rick helped Bayern Munich to wrap the second win in Group F against hapless Dinamo Zagreb, at the second round of UEFA Champions League's group stage on Tuesday.

Relentless Bayern Munich showed now mercy with Dinamo Zagreb, who suffered their first loss after a 45-game unbeaten streak, as Josep Guardiola's men scored four goals within 28 minutes to seal the deal ahead of time at outsold Allianz Arena.

The "Bavarians" took the reins on home soil from the opening whistle to secure a fairy-tale start on home soil after new arrival Douglas Costa broke the deadlock following a fast break with a low shot into the near post corner at the 13th minute.

Dinamo Zagreb's defender Filip Benkovic invited the hosts with a moment of madness, allowing Thiago Alcantara to set up for Robert Lewandowski, who tapped home the two-goal advantage into the open goal nine minutes later.

Zoran Mamic's men were unable to keep up the resistance as Bayern kept it bowling to triple the lead through Mario Goezte. The German international made use of a one-two with Kingsley Koeman to beat Zagreb goalkeeper Eduardo into the bottom right at the 25th minute.

As if that weren't enough Bayern added the fourth goal before the break after Thiago Alcantara's through ball found Polish international Lewandowski inside the box only three minutes later.

However, Bayern wasn't done with the scoring against harmless visitors from Zagreb as Robert Lewandowski sewed up his hat rick following a corner kick to put the game beyond doubt ten minutes into the second half.

With the 5-0 victory, Bayern Munich reaped their tenth straight victory into the season meanwhile Dinamo Zagreb suffer their first loss since last November.

The German record champions lead Group F with six points, followed by Olympiacos and Dinamo Zagreb both with three points and Arsenal with zero points.