BERLIN (AP) -- Fireworks and masked pitch invaders marred Berlin's first Bundesliga derby involving teams from each side of the formerly divided city on Saturday.
Sebastian Polter scored the only goal in the 90th minute for promoted Union Berlin of the former East Germany to defeat Hertha Berlin in a hard-fought struggle, one week before the city marks 30 years since the fall of the Berlin Wall.
But the home fans' celebrations were delayed by 10 minutes of injury time due to an earlier interruption caused when fireworks from Hertha fans landed on the pitch.
One landed dangerously close to the Union bench, prompting referee Deniz Aytekin to suspend play and lead both teams off the pitch. The stadium announcer warned the game was in danger of being called off.
Aytekin said officials consulted with police before deciding to continue.
''The most important thing is that no one gets hurt. This has nothing to do with football,'' Aytekin said.
More fireworks from the Hertha block landed on the pitch once the game ended, when a group of masked Union fans tried to force their way across the pitch to confront the visiting supporters.
The masked fans were confronted by Union goalkeeper Rafal Gikiewicz, who pushed one back and angrily urged them to return to their block. Other Union players including Keven Schlotterbeck helped out.
It was an intense encounter from the beginning.
Union, which was promoted this season, is the first Bundesliga team based in Berlin to have played in East Germany's Oberliga, and Hertha is reluctant to share the spotlight.
''It's about showing that Hertha is the capital club, the No. 1 in Berlin,'' Hertha coach Ante Covic said of the derby before the season.
Anticipation had been growing for weeks. Many looking for tickets outside Union's stadium in Kopenick before kickoff were left disappointed.
Fans made their singing heard above the stadium music before the game, then sang along as the Union anthem was blared out to a choreography based on Greek mythology featuring a Perseus in Union colors slaying the Hertha-Medusa.
Huge banners flanked by Greek pillars covered a whole stand with the message: ''On arrival at football's Olympus, after a seemingly endless odyssey, you will now fight your greatest battle. For your opponent, it will mean the following: first the sin, now death.''
Hertha fans responded with a blue and white choreography and a first flurry of fireworks that prompted a chorus of whistles from their counterparts.
The fans' excitement seemed to carry onto the pitch, where Union made a frenzied start and almost scored when Christopher Lenz struck the post in the third minute.
Hertha gradually settled but there were few real chances as the sides canceled each other out in a midfield scrap.
The second half began with fireworks from both sets of fans. Fireworks are not permitted in German soccer stadiums, but the Union fans began with a huge display of flares before the Hertha fans responded by shooting fireworks onto the pitch and Aytekin led the teams off.
Police ensured the game didn't go up in smoke, but there was still more drama to come.
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