A debut goal from Edson Buddle helped Ingolstadt earn a point against David Yelldell and a tough Duisburg squad while Matt Taylor's eighth goal of the season was not enough to help Ahlen past his previous team Koblenz.
Hamburger SV 1 - 0 Eintracht Frankfurt
Ricardo Clark continued his run in the Frankfurt central defense, putting in a solid performance on Friday in their close loss at Hamburg.
Hamburg youngster Änis Ben-Hatira had the first chance for the hosts after nine minutes when he got past Clark's central defense partner Sebastian Rode, but was beaten to the ball by keeper Oka Nikolov who deflected it to safety.
Frankfurt's Martin Fenin wove his way into the area from the left side in the 17th minute before getting a low shot off, however it lacked any power and was easily grabbed by Frank Rost with little danger.
A largely dour first half forced Hamburg coach Armin Veh to bring on Mladen Petric at halftime with hopes of creating some spark on the attacking end, and the move paid dividends midway through the half.
Ben-Hatira received a long crossfield pass on the right side and easily beat Frankfurt left back Nikola Petkovic before sending the ball into the six-yard box for Petric to knock in with his sliding shot for his fifth goal of the season.
Frankfurt's push towards goal was never able to pick up any steam throughout the rest of the game, ultimately giving the hosts little trouble to hold on for the full three points.
Frankfurt drop one spot to ninth place with the loss, but will have a good chance to jump in the standings on Sunday when they host Michael Bradley and bottom team Borussia Mönchengladbach.
Hannover 96 0 - 1 FC Schalke 04
A first-half goal by Schalke forward Raul was enough to send Steve Cherundolo and Hannover to just their second loss in eight games on Friday evening.
Hannover midfielder DaMarcus Beasley was not included in head coach Mirko Slomka's roster for the encounter.
Schalke nearly took the lead in the 12th minute when Raul was served up a perfect ball 15 yards straight out, but his blast was blocked by Karim Haggui to keep Hannover in the game.
Emanuel Pogatetz tested Schalke's Manuel Neuer in the 21st minute with a blazing free kick from 30 yards out, however the German national keeper had no problems to deflect the ball out of danger.
The visitors did take the lead three minutes past the half-hour mark thanks to a nifty display of link-up play on the wing. Klaas-Jan Huntelaar, Julian Draxler and Lukas Schmitz brought the ball up the left side with a series of short passes to beat the Hannover defense, allowing Schmitz to nail a cross to Raul who neatly flicked the ball into the net in midair.
Cherundolo triggered one of Hannover's best chances to equalize in the 64th minute when he fooled his defender on the right side and whipped a cross into the six-yard box. While the ball was initially headed just outside the top of the area, it fell directly to Sergio Pinto, who chested it down and sent a blast which Neuer deflected out for a corner with a diving save.
Pogatetz got his head on the subsequent corner from Pinto to once again test Neuer with a shot towards the upper left corner, however the German national keeper proved his credentials with a high leap to barely push the ball to safety.
The loss drops Hannover into third place, in a tight race with several other teams at the top of the standings for the league's Champions and Europa league spots. They face a tough road test on Friday evening when they pay a visit to fellow challengers Bayer Leverkusen.
FC Ingolstadt 04 1 - 1 MSV Duisburg
See David Smith's Press Box Report.
Alemannia Aachen 4 - 2 Karlsruher SC
Luis Robles had a tough day in the office, forced to pick the ball out of his own net four times in Karlsruhe's defensive collapse in Aachen on Saturday.
The game got off to an inauspicious start for Karlsruhe when Timo Achenbach's deflected cross from the left edge of the penalty area landed in a perfect spot for Zoltan Stieber to one-time from short range just inside the left upright for the fifth-minute lead.
The visitors pulled even just before the 20-minute mark, with Andreas Schäfer placing a long free kick from the left side to the right of goal, where Timo Staffeldt was waiting to slam the ball past Aachen keeper David Hohs.
Momentum quickly shifted back to the hosts, however, as a pair of mistakes by Robles made it easy for Aachen. A scuffed kick by the American out of his own area in the 22nd minute gave Stieber the ball in the left flank with plenty of room to operate.
The Hungarian striker worked his way towards the touchline and lofted a cross towards the far post, however as Robles had prematurely come off his line, Benjamin Auer was free to leap high and head the ball uncontested into goal for the lead.
They added a third goal four minutes later, as Tolgay Arslan found Robles again off his line, and blasted a long-range shot just over his reach to seemingly put the game away for the hosts.
Robles prevented the game from becoming a complete disaster, coming up big to thwart Arslan in the 54th minute and making a reflex stop of a shot by Marco Höger four minutes later.
Karlsruhe pulled to within one goal in the 65th minute after providing heavy pressure around the Aachen goal, with Gaetan Krebs on target with a low 20-yard shot inside the left corner.
A bad giveaway by the Karlsruhe defense with one minute left in regulation put to rest any hopes of pulling a point from the game, with Stieber earning his 12th assist of the campaign to set up Sergiu Marian Radu for a short tap-in to double the margin.
Karlsruhe remain in the 2. Bundesliga's 16th-place relegation playoff spot, one point behind both Oberhausen and Osnabrück, and face a tough road on Sunday when they host promotion-hunting Cottbus.
Rot Weiss Ahlen 2 - 3 TuS Koblenz
Matt Taylor scored from the spot for his eighth goal of the season for Ahlen on Saturday afternoon in 3. Liga makeup action, however they were unable to overcome a trio of goals from Koblenz on the way to their sixth loss of the season.
Saturday's game marked Taylor's first opportunity to face the team with which he made his first steps into Europe, and while Ahlen would ultimately come out of the encounter empty-handed he was nevertheless able to leave his mark in the high-scoring affair.
Following an opening half which saw both teams deadlocked at zero, the game immediately picked up intensity, with a defensive error by the hosts practically gifting Koblenz the lead in the 50th minute.
Rot Weiss defender Robert Fleßers made an errant pass from the backfield directly to the feet of Koblenz player Marcus Steegmann, who was tripped up on his path towards goal in the penalty area by central defender Daniel Flottmann, allowing Christian Pospischil to give the visitors the lead from the spot.
Johannes Rahn doubled Koblenz's lead two minutes later after a corner, however Ahlen pulled one back on the hour mark, thanks to a return favor from the Koblenz defense.
The referee judged a visiting defender to have fouled Marcus Piossek in the area, allowing Taylor to step up and bury his penalty past Dieter Paucken for his eighth goal over his twelve games with the team.
The team's hopes of a come-back were squashed, however, as Ole Kittner put Koblenz ahead by two goals after 67 minutes, and while Kevin Wölk gave the hosts some brief hopes by scoring on a direct free kick with two minutes left in regulation, the visitors held strong to take all three points.
Ahlen drop to 11th place, but will have a quick turnaround as they hit the field on Tuesday evening against Werder Bremen II to make up December's game which was postponed due to heavy snowfall.
Michael Bradley came off the bench for the last four minutes of Borussia Mönchengladbach's 3-1 loss at home to local rivals Bayer Leverkusen on Sunday.
Freiburg's Daniel Williams is out for some time with a knee injury while Nürnberg midfielder Timothy Chandler played the final 35 minutes as a second-half substitute in a 1-1 draw between the two teams on Saturday.
Hertha Berlin midfielder Alfredo Morales played for the final four minutes on Sunday afternoon as the team's 3-2 win over Fortuna Düsseldorf moved them to the top of the 2. Bundesliga standings.
Bobby Wood suited up with 1860's first team for the first time on Friday night, but was an unused substitute in their 1-0 win at Osnabrück.
FC Bayern II midfielder Fabian Hürzeler is still waiting for his first call-up to the team's gameday roster, and was not in uniform on Saturday for their 2-0 loss at Wacker Burghausen in a makeup of December's game which had been postponed due to inclement weather.