Union, fifth last season, made sure they kept bragging rights in the capital after beating Hertha three times, including in the German Cup, last season.

Jordan Siebatcheu scored on his Bundesliga debut on Saturday, sending a glancing header past Hertha keeper Oliver Christensen.

With Hertha posing no threat and leaving big gaps in their defence, Union struck again five minutes after the restart when Sheraldo Becker charged into the box and flicked the ball past Christensen.

It got even worse when Robin Knoche headed in, subject to a VAR review.

Hertha scored in the 84th through Dodi Lukebakio to cut the deficit.

Borussia Moenchengladbach also enjoyed a winning start to their season with a 3-1 victory over 10-man Hoffenheim while Freiburg fired four past hosts Augsburg.

In the evening game, a first-half goal by Borussia Dortmund captain Marco Reus was enough to give last season's runners-up a 1-0 win over Bayer Leverkusen.

However, the win was overshadowed by an injury to new signing Karim Adeyemi.

The Germany forward Adeyemi was taken off in the first half having taken a knock on his foot earlier in the game.

Champions Bayern Munich kicked off the season on Friday with a sensational 6-1 demolition of Eintracht Frankfurt.

Australian Associated Press