Undefeated Bayer Leverkusen have secured their first Bundesliga title with a 5-0 victory over Werder Bremen, breaking an 11-year stranglehold on the league by Bayern Munich. Xabi Alonso’s team, who have now gone a league-record 29 matches without defeat this season to secure their first trophy since 1993, have a 16-point lead over Bayern with five matches remaining.

They can add more titles this season, reaching the German Cup final and the Europa League semifinals where they will take on AS Roma.

Leverkusen left nothing to chance and sealed their title win at the first opportunity with Florian Wirtz bagging a hat trick in a win that stretched their unbeaten run across all competitions to a remarkable 43 games this season.

Victor Boniface – starting a Bundesliga game for the first time since December because of injury – settled Leverkusen’s nerves with the opening goal from the penalty spot before Granit Xhaka hit an audacious long-range shot to make it 2-0 with half an hour to go. Fans had already stormed onto the field when Leverkusen scored its fourth goal with seven minutes to go, and the final minutes were played in thick red smoke from supporters’ pyrotechnics while players on Leverkusen’s bench clapped along to songs, danced and hugged one another.

The fifth goal in the 90th minute brought more fans onto the field – hundreds this time – and the referee ended the game amid confusion and jubilation. Thousands of supporters crowded the field, waving flags, flares and cardboard copies of the Bundesliga trophy. Leverkusen had finally shed its reputation as perennial runner-up after five second-place finishes in the league and one in the Champions League. The title puts the spotlight firmly on an industrial city of just under 170,000, which has been overshadowed by larger, more famous neighbours.

The club started as a workers’ team for the Bayer pharmaceutical giant 120 years ago and is a rare exception in Germany, where most clubs are majority controlled by members under the so-called 50+1 rule.