(Reuters) - Bayern Munich set an unbeaten record, Borussia Dortmund lost again, Bayer Leverkusen's Son Heung-Min scored a hat-trick and there was goal line controversy as 27 goals were scored in six Bundesliga matches on Saturday.
South Korea forward Son led Bayer Leverkusen to a 5-3 win over his former club Hamburg SV which pulled them level on points with second-placed Dortmund in a match featuring calamitous defending and superb finishing by both sides.
Dortmund, beaten 1-0 at home by Arsenal in the Champions League on Wednesday, were sunk by a superb Ivica Olic strike in their 2-1 defeat at Wolfsburg as last season's runners-up showed worrying signs of a slump.
Bayern Munich beat Augsburg 3-0 to set a Bundesliga record of 37 matches undefeated in what was their seventh straight home win and which increased their lead at the top to four points.
Last season's treble winners, who overhauled the record set by Hamburg 30 years ago, have not been beaten in the league since October 28 last year when they lost 2-1 at Leverkusen.
Bayern have 32 points from 12 games, four clear of Dortmund who are level with Leverkusen. Six points further back are Borussia Moenchengladbach whose 3-1 home victory over winless Nuremberg contained the goal line controversy.
Bottom side Nuremberg were 2-1 down when Josip Drmic's shot bounced down off the crossbar on to the line. Despite appeals, no goal was given and television replays were inconclusive.
Drmic had put Nuremberg ahead after 21 minutes but Juan Arango levelled in the 72nd before a Niklas Stark own goal after 75 put the hosts in front. Patrick Hermann's effort three minutes from time sealed the win.
At Wolfsburg, Dortmund went ahead in first-half stoppage time with a Marco Reus free kick.
Ricardo Rodriguez equalised for the Wolves from a free kick in a thrilling second period before Olic scored the winner with a superb curling effort while Dortmund striker Robert Lewandowski had two penalty appeals turned down.
"It was a game with, let's say, lots of players on the floor and lots of free kicks. In some situations, everything went against us," said Dortmund coach Juergen Klopp. "They could have given us one of the two penalties."
Unheralded Leverkusen suggested they could be Bayern's biggest challengers this season after winning an eight-goal humdinger against former Netherlands coach Bert van Marwijk's Hamburg.
Son, who joined Leverkusen from Hamburg this season, scored two superbly-taken goals in the first 16 minutes, Maximilian Beister pulled one back for Hamburg and Pierre-Michael Lasogga levelled in the 50th minute.
Son put Sami Hyppia's Leverkusen back in front five minutes later with another coolly-taken goal and set up a fourth for Stefan Kiessling to extend Leverkusen's lead after Hamburg gave the ball away.
Lasogga pulled another back, his eighth of the season, after Son lost possession near the corner flag, but Gonzalo Castro wrapped up the game in the 89th minute by chipping Rene Adler after Hamburg were again caught on the break.
"We lost this game through our own mistakes," said van Marwijk, who put his head in his hands in exasperation after the last two Leverkusen goals.
There was no such drama in Munich where record-breaking Bayern cruised to a typically straightforward home win.
Jerome Boateng put them ahead after five minutes and Franck Ribery ended the game as a contest when he scored with a rasping free kick just before halftime. Thomas Mueller rounded off the win with a last-minute penalty.
"The early goal made it easier but we didn't play so well," coach Pep Guardiola told Bayern's website (www.fcbayern.telekom.de).
"In the second half, we got better and created some chances. I hope that the players return fit after the international break."
Kevin-Prince Boateng scored with two headers to help Schalke 04 to a 3-1 win over Werder Bremen after they had trailed at halftime to a Felix Kroos effort.
Jefferson Farfan netted the other for Schalke as they recaptured some form following their 3-0 midweek defeat at Chelsea in the Champions League.
Mid-table Hoffenheim, who have scored 28 goals and conceded 28 in 12 league games, were involved in another goalfest but lost 3-2 at home to Hertha Berlin.
Anis Ben-Hatira and Ramos struck to give Hertha a 2-0 lead before Hoffenheim replied with a penalty and free kick by Sejad Salihovic, only for Ramos to head the winner six minutes from time.
(Reporting By Brian Homewood, editing by Tony Goodson)