Cologne - A first defeat of the season for FC Bayern München, a five-time Bundesliga champion at the bottom of the pile and more than just a handful of heroic performances in front of goal: the Bundesliga returned with attitude on Matchday 18. looks back on the five major talking points to have emerged from the opening round of Rückrunde fixtures...

Without doubt the biggest story of the weekend was Wolfsburg's 4-1 triumph over league leaders Bayern. Two goals each from Bas Dost and Kevin De Bruyne capped a clinical display, which stood as a fitting tribute to the late Junior Malanda who was remembered with a minute's applause and a stunning choreography before the encounter. Their first league defeat of the season, Bayern's advantage at the top now reads eight points.

At the other end of the scale,14 points off a place in the top four no less, sit Borussia Dortmund. Jürgen Klopp's side kept only their third clean sheet of the season in Saturday evening's goalless draw at Bayer 04 Leverkusen, but not even that was enough to spare them a place on the bottom rung of the league ladder following SC Freiburg's 4-1 win over Eintracht Frankfurt earlier in the day.

Key to Freiburg's come-from-behind success was SV Werder Bremen loanee Nils Petersen, who came off the bench in the second half to net a stunning hat-trick. The 26-year-old hadn't scored since April 2014 prior to the game, but rather like 1. FC Köln's two-goal Hamburger SV slayer Marcel Risse and Wolfsburg's Dost, looked a player reborn after a disappointing Hinrunde.

A similar tale unfolded in Mainz, where Yunus Malli scored his maiden Bundesliga brace and first league goals of the season to help the hosts end a run of nine games without a win by beating SC Paderborn 07 5-0. Kasper Hjulmand's side were only a goal to the good at the interval, but turned on the style after the restart to secure three much-needed points and break the seemingly never-ending winless cycle.

Bremen, meanwhile, picked up where they left off at the end of 2014, following up their 2-1 success against Dortmund with a comfortable 2-0 win at home to Hertha Berlin. Making his first competitive appearance since suffering knee ligament damage in training last November, Franco Di Santo took his league tally to eight for the season with a goal in either half as the Green-Whites moved three points clear of the relegation zone into 12th.