Bayer Leverkusen went one point clear at the top of the Bundesliga after a 3-0 win at struggling Mainz although Bayern Munich can regain pole position later on Saturday.

Union Berlin meanwhile slumped to their fifth straight defeat of the season in all competitions. 

Leverkusen, who have claimed all points on offer in the league this season other than a 2-2 draw away at Bayern, took the lead after 18 minutes as wing-back Jeremie Frimpong forced Mainz defender Sepp van den Berg into an own goal.

Dead-ball specialist Alejandro Grimaldo doubled Leverkusen's lead with a pinpoint free-kick before Germany winger Jonas Hofmann scored a third to round out the win. 

Hofmann, who moved to Leverkusen in the summer having spent seven years at Borussia Moenchengladbach, now has three league and three assists in the league for his new club. 

Mainz have just one point and are bottom of the table after six matches. 

Union Berlin's poor start to the season continued, losing 1-0 away at promoted Heidenheim thanks to a second-half goal from Jan-Niklas Beste.

Beste's free-kick deflected into the net midway through the second half, consigning Champions League participants Union to their fifth consecutive defeat in all competitions for the first time since 2004.

Surprise package Stuttgart continued their remarkable rise this season, winning 2-0 at Cologne thanks to a brace from Deniz Undav. 

Stuttgart, who needed to win a relegation playoff against Hamburg last season to stay in the top division, now sit outright second after six matches. 

The game did however mark the first time this season that striker Serhou Guirassy, who had a remarkable ten goals from five league matches heading into the fixture, failed to get on the scoresheet. 

Wolfsburg striker Jonas Wind, another one of this season's early top scorers, did however continue his strong form in front of goal, scoring a brace to help his team to a 2-0 home win over Eintracht Frankfurt. 

Wind now has seven of his team's nine goals in the Bundesliga this season. 

Elsewhere, a double from Alassane Plea took Gladbach to their first win of the season, a 3-1 victory away at Bochum. 

Florian Neuhaus opened the scoring for the visitors and Plea added two by halftime. 

Bochum's Anthony Losilla pulled one back in the secoond half and had another ruled out in injury time as Gladbach held on to win. 

In Saturday's late game, Bayern can re-take top spot in the Bundesliga table with a win away at RB Leipzig.