Xabi Alonso's Bayer Leverkusen equalled the best start to a Bundesliga season in history as they returned to the top of the table with a dominant 4-0 home win over Union Berlin on Sunday.

The victory means Leverkusen have amassed 31 of a possible 33 points after 11 matches, equal to the record set by Pep Guardiola's Bayern Munich in 2015-16.

Bayern's 4-2 victory over Heidenheim saw the Bavarians spend Saturday night atop the standings but Alonso's men were dominant on Sunday, winning with goals from Alex Grimaldo, Odilon Kossounou, Jonathan Tah and Nathan Tella.

Alonso praised his "patient" team, saying "we're very satisfied with what we've done from the previous international break to this one... a lot of away games and every game a win."

"The feeling is great at the moment."

"That was clear -- a clear difference in class," Union manager Urs Fischer said to DAZN, saying his side were in a "relegation battle."

Leverkusen defender Florian Wirtz cut holes in the Union defence early but striker Victor Boniface was off target, blasting wide twice in the opening minutes.

The home side hit the lead after 24 minutes, Grimaldo stopping on the edge of the box before chipping a dipping shot over Union goalie Frederik Ronnow.

Grimaldo, 28, who was called up to the Spain squad for the first time this week, has six goals in the league since moving from Benfica in the summer.

Union lost centre-back Leonardo Bonucci to injury early and struggled to contain the home side's quick passing, a wide-open Boniface heading directly at Ronnow late in the first half.

Kossounou headed in a Jonas Hofmann corner midway through the second-half to double the home side's lead. It was the Ivorian's goal for Leverkusen in his third season at the club.

Germany centre-back Tah hammered in a corner with just over 15 minutes remaining.

Tella scored two minutes after coming on, the winger finishing a length-of-the-field attack for his side's fourth.

Leverkusen have now won 16 and drawn one of 17 games in all competitions this season.

Union Berlin, who finished fourth to qualify for the Champions League last season, finish the weekend bottom of the table, having lost their last nine in a row.

Elsewhere on Sunday, RB Leipzig won 3-1 at home to Freiburg to leapfrog Borussia Dortmund into fourth place.

Paris Saint-Germain loanee Xavi Simons opened the scoring after just six minutes for Leipzig, but Freiburg's Merlin Roehl scored spectacular solo goal to level the scores just before half-time.

Belgian striker Lois Openda gave Leipzig the lead from the spot with ten minutes remaining, Christoph Baumgartner scoring a minute later to seal the win for the home side.

Eintracht Frankfurt came from two goals down to draw 2-2 at Werder Bremen.

Bremen striker Marvin Ducksch celebrated his first Germany call-up with a penalty and Rafael Borre scored to give Bremen a 2-0 lead, but Ellyes Skhiri and Hrvoje Smolcic scored second-half goals to claw back a point.