Dortmund will attempt to slash the gap with a win over their domestic rivals, throwing the title race wide open with just nine matches to go.Bayern's shock 2-1 loss at home against Mainz 05 on Wednesday, coupled with Dortmund's victory over Darmstadt 98, has pumped much-needed life into what was until now a stale affair.The Bavarians had gone 11 points clear last Saturday, before Dortmund won on Sunday, and seemed to be cruising towards a record fourth Bundesliga title.Their second loss of the season could not have come at a worse time as they chase a treble of titles, with coach Pep Guardiola leaving at the end of the season to join Manchester City and pressure mounting with every match."We will do everything to cut the deficit even further," said Dortmund coach Thomas Tuchel, who rested eight players against Darmstadt, including winger Marco Reus."Bayern's lead has melted away. Now we have an even better starting position. We have worked hard to get ourselves in this position and now the ball is in our court. I hope we can now show the same energy.""Bayern are still in control but we have a chance to make this race tight again."Dortmund have had a stellar season so far with most previous Bundesliga champions having had fewer points at this stage.While Bayern's dominance in Germany under Guardiola has been undisputed in the previous two seasons, the Spaniard needs to step it up a gear if he wants to leave with his third successive German league title.Not even disgraced former president, Uli Hoeness, released this week from prison on suspension after 21 months following conviction for tax evasion, and sitting in the stands for his first game on Wednesday could inspire Bayern to turn the match around."We had our chances to win against Mainz but it was just not enough," Guardiola told reporters. "We still have a lot of work to do if we are to defend our title."Guardiola also rotated, giving Xabi Alonso, Philipp Lahm and several others a rest ahead of Saturday's crunch match.Hertha Berlin,, who beat Eintracht Frankfurt in midweek, are third on 42 points, 15 behind Dortmund, and will play Hamburg SV as they look to keep Borussia Moenchengladbach, three points behind in fourth place at bay...