The title race is a psychological battle as much as a sporting one. Borussia Dortmund had Roman Bürki, Jadon Sancho and Mario Götze to thank against Mainz on Saturday, but questions over mentality remain.Roman Bürki used his chest to save the first effort, and then a combination of flailing limbs to scramble away the rebound. Finally, when the ball came back in his direction for the third time in as many seconds, he smothered it on the line. Borussia Dortmund had survived. The relief inside the Westfalenstadion was palpable and cries of "Roman Bürki" rained down from the Südtribüne in grateful praise of the Swiss stopper whose heroics had secured three vital points, sending Dortmund back to the top of the Bundesliga for at least a day. "I'm not happy with the second half," the Bürki told broadcaster Sky after making nine saves in the win over Mainz. "I feel like we got scared after they made it 2-1. We had our backs against the wall in our own stadium." A week on from their mauling in Munich, Borussia Dortmund were expected to show a reaction and send a signal that the Bundesliga title race was still alive. In the first half, they did, thanks to more brilliance from Mario Götze and Jadon Sancho. Götze, surprisingly left out of the starting eleven against Bayern, set up Dortmund's first with an exquisite turn and cross. He sparked the move which led to the second too. Sancho scored both, the 19-year-old's ninth and tenth Bundesliga goals this season. Terrific then tired Two goals to the good and Dortmund were flying, any lingering doubts from their battering in Bavaria seemingly banished. But it's been a long season for Lucien Favre's young team and, as the second half wore on, the physical and mental fatigue began to show. Mainz's pressure grew. Dortmund wilted visibly, as passes went astray and red shirts were first to every loose ball. "The first half was fine but I can't explain why we stopped playing football in the second half because Mainz were pretty much dead," said captain Marco Reus, who had been brutally honest in his criticism of himself and his teammates last week. "It's a question of mentality. We have a lot of young players, and we need to stay relaxed and keep having fun." It's difficult to put a finger on the mentality of this Borussia Dortmund team. In the weeks building up to the game in Munich, they proved they had the belief in their own ability to win games late on against Stuttgart, Hertha Berlin and Wolfsburg – only to meekly cast themselves in the role of David when facing Goliath in the Allianz Arena. The psychological meaning of this nerve-jangling win over Mainz will be made clear at the end of the season. Should Dortmund survive a tough run-in (Freiburg, Schalke, Bremen, Düsseldorf and Gladbach) and capitalize on a Bayern slip-up to lift the title, this narrow win will be remembered as a mental triumph, a turning point in the title race. But if similar lapses occur between now and mid-May, it will go down as just another day on which Dortmund's psychological frailty cost them the title. The individual heroics of Götze, Sancho and Bürki will have been in vain.
