Dortmund (Germany) (AFP) - A first-half Serhou Guirassy double and four Julian Ryerson assists helped Borussia Dortmund to a 4-0 home win over Mainz on Friday, pulling them three points behind Bundesliga leaders Bayern Munich.

Wing-back Ryerson laid on four Dortmund headers, including Guirassy’s brace and one each from Maximilian Beier and Ramy Bensebaini in Dortmund’s biggest league win this season.

Bayern, who play at struggling Werder Bremen on Saturday, were 11 points clear of Dortmund at Christmas having played the best opening half to a season in Bundesliga history.

A six-match winning run has let Dortmund cut into that lead. The two face off in Dortmund in two weeks in a match with huge title ramifications.

Dortmund coach Niko Kovac told Sky: “When you win on a Friday you can put your feet up for the rest of the weekend. Regardless of what happens tomorrow, we can be pleased.”

“All of Germany is pleased to see (a title race) but we can only focus on ourselves.”

Ryerson told Sky Germany “it was nice to decide things so early – it gives us a good feeling.

Asked if he took inspiration from set-piece kings Arsenal with three of his assists coming from dead-ball situations, Ryerson said he “hadn’t watched much” of the Premier League leaders, but added: “whether it’s Arsenal or not, it’s working well.”

Dortmund threw away the 2022-23 Bundesliga title with a 2-2 final-day home draw versus Mainz, but Kovac said on Wednesday he avoided the topic all week, telling reporters “I don’t want to speak of trauma.”

Dead last in December, Mainz have climbed to 14th under new coach Urs Fischer, losing just one of nine league games since the Swiss arrived in the dugout.

Guirassy put Dortmund in front after 10 minutes when he headed in a Ryerson free kick.

Ryerson created Dortmund’s second five minutes later when Beier headed his cross home.

Dortmund extended their lead just before the break and the Norwegian was again the architect, swinging a corner right to Guirassy.

Struggling with a form slump with just one goal in 10 league games either side of Christmas, the Guinean now has five goals in his past three games.

With six minutes remaining, Ryerson swung in another corner which Bensebaini headed in through a crowded box.

Dortmund have had a tendency to fade late and have dropped 10 points from winning positions in the final 10 minutes this season, but held firm to record a dominant victory four days out from hosting Atalanta in the Champions League knockout round.