Schalke 04 remain in the hunt for the Bundesliga title after the Royal Blues beat Hoffenheim 2-0 on Saturday evening while Bayern Munich went top of the table with a 3-0 win over Mainz.
Schalke are third after goals by striker Kevin Kuranyi and midfielder Lukas Schmitz saw off Hoffenheim who drop to ninth in the table.
The Royal Blues are now level on 41 points with Leverkusen, just one behind Bayern, but with Leverkusen facing strugglers Freiburg on Sunday evening, Bayern can expect to lose their place at the top of the table.
Earlier Dutch winger Arjen Robben scored his second goal in two matches to seal Munich’s seventh-straight league win.
Having scored the winner in the 3-2 victory at Bremen the week before, Robben curled in another free-kick against Mainz to give Louis van Gaal-coached Bayern three more points after heavy snow made playing conditions difficult.
“The weather was not good, it was the same for both sides, but it worked out for us,” said Robben after the ball had slipped out of the Mainz goalkeeper’s hands for the first Bayern goal.
“We were lucky with the first goal and things went well after that.
“The coach told us to stay calm at the break because we were still level and our patience paid off.”
Bayern’s Mario Gomez and Daniel Van Buyten had fired the German giants into the lead before Robben stepped up with the third goal.
The home side took the lead amidst heavy snow when Van Buyten headed home after a cross from Robben on 58 minutes.
French winger Franck Ribery, who continues to work his way back to fitness after a knee injury, came off the bench with 30 minutes remaining.
Ribery and Robben combined to free Germany defender Philipp Lahm down the right flank who fired in a cross which Gomez slotted home on 75 minutes before Robben struck with four minutes remaining.
Elsewhere, Bremen coach Thomas Schaaf is in a precarious position as his side have now gone seven German league games without a win after they went down 4-3 at midtable Borussia Moenchengladbach.
The home side raced into a 3-0 lead after just 18 minutes before Mesut Oezil and Claudio Pizarro pulled goals back for Bremen and captain Torsten Frings converted a penalty with six minutes left to guarantee a frantic finish.
Second from bottom Nuremberg picked up only their second win in their last 10 games when they won 3-1 at Hanover and the result leaves bottom side Hertha Berlin five points adrift after they drew 0-0 with Bochum in the capital.
Cologne are up to 12th after their second consecutive win having beaten Eintracht Frankfurt 2-1.
With defending champions Wolfsburg drawing 1-1 at Hamburg on Friday, fourth-placed Dortmund face Stuttgart on Sunday.
Under former Tottenham Hotspur boss Christian Gross, who took over from Markus Babbel in December, Stuttgart have moved up to 13th in the table.