Raul Gonzalez scored a hat-trick as Schalke 04 continued their Bundesliga recovery with a 4-0 drubbing of Werder Bremen, dpa reported.
The former Real Madrid star Raul was on target in the 45th, 53rd and 71st as Schalke claimed their biggest victory of the season. Free-falling Bremen had Philipp Bargfrede dismissed late in the game.
Borussia Dortmund, meanwhile, rallied to beat hosting SC Freiburg 2-1 to maintain a seven-point lead over Mainz 05, who prevailed 3-2 at Borussia Moenchengladbach for their first win in five games.
Bayer Leverkusen were also bidding to remain seven points behind Dortmund, provided they defeated champions Bayern Munich later Saturday.
Schalke are 13th with 13 points after a second win in three unbeaten games.
Christoph Metzelder headed the opener with a little help of Bremen goalkeeper Tim Wiese before Raul, criticised by coach Felix Magath just a few weeks ago, made his biggest statement since joining Schalke in summer.
The Spanish veteran tapped home the second on the stroke of half-time, took advantage of a defensive error in the 53rd and cooly lobbed over Wiese in the 71st.
Bargfrede's dismissal on a second bookable offence added to the misery of Bremen, who lost for the third time in four winless games and are stranded in 11th place with 15 points.
"We make mistakes and can't stop making them. We don't fight back, we don't hurt our opponents," said Bremen coach Thomas Schaaf after the latest setback.
In Freiburg, the hosts scored in bizarre and slightly controversial fashion in the 26th minute.
Dortmund goalkeeper Roman Weidenfeller, under pressure from Cedric Makiadi, failed to control a free-kick. Papiss Demba Cisse sent the loose ball towards goal with the back off his head, Neven Subotic cleared on the goalline, but against the body of the Germany defender Hummels from where it bounced into the net.
The leaders protested in vain that Weidenfeller was impeded but eventually managed a late comeback from the substitute Lewandowski in the 77th and an own goal by Mensur Mujdza two minutes later.
Jakub Blaszczykowski incredibly missed a third when he fired high over an empty goal which almost backfired as Freiburg's Julian Schuster headed against the crossbar in stoppage time.
"It was a tight game. We didn't play well in the first half but I believe the first goal should have not been given," said Dortmund coach Juergen Klopp.
Substitute Sami Allagui struck twice late in the game as Mainz ended a negative trend with the victory in Moenchengladbach, Hanover 96 moved into fourth place with a last-minute 3-2 victory over SV Hamburg from Maik Hanke's header, Eintracht Frankfurt crashed 4-0 at home against Hoffenheim and hosting Nuremberg lost 3-1 against Kaiserslautern.