Haaland takes tally to seven in three games with another Dortmund double

Erling Braut Haaland insisted he needs to get fitter despite making it seven goals in three games for Borussia Dortmund with another double in Saturday's 5-0 Bundesliga thrashing of Union Berlin, while Bayern Munich went top of the table. The 19-year-old Haaland, who had netted five times in his first two appearances after signing from Salzburg, scored either side of half-time at Signal Iduna Park after being handed his first Dortmund start by coach Lucien Favre. Haaland's tally is the most by any Bundesliga player in their first three league matches. However, the Norwegian says he still needs to get fit after a knee injury last month restricted his training. "It was pretty tough today, but it was also nice to play from the start," Haaland told Sky. "I have to get even fitter, I am still not 100 percent." Dortmund moved to third in the table, three points behind leaders Bayern Munich, who beat Mainz 3-1. Previous pace-setters RB Leipzig can regain top spot if they beat fourth-placed Borussia Moenchengladbach at home later on Saturday. England winger Jadon Sancho became the first teenager to score 25 Bundesliga goals when he started Dortmund's rout with a looping shot past Union goalkeeper Rafal Gikiewicz. Haaland then added to his record run on 18 minutes when he was presented with a simple tap-in from a Julian Brandt cross. The hosts were dominating as Haaland won a penalty, which captain Marco Reus converted midway through the second half. Midfielder Axel Witsel made it 4-0 on 70 minutes, firing home after Sancho's brilliant pass took out two defenders and set up his Belgian team-mate. Haaland completed the scoring when a Brandt back-heel fell into his path and he drilled his shot past the despairing Gikiewicz. - 'Hard to stop' - In Mainz, goals by Robert Lewandowski, Thomas Mueller and Thiago Alcantara fired Bayern two points clear with their sixth straight league win. The reigning champions men host title rivals Leipzig next weekend. "We have six wins in a row now, which gives us a lot of self-confidence and if we keep playing like this, we will be very hard to stop," said Bayern full-back David Alaba. Bayern wasted no time taking the lead despite the sodden conditions as the Bundesliga's top scorer Lewandowski netted his 22nd league goal of the season on just eight minutes to herald a powerful first half by the visitors. Mueller hit their second on 14 minutes, finishing a move he started after Lewandowski and Leon Goretzka cut the Mainz defence open. Alcantara made it 3-0 on 30 minutes by beating three defenders with superb footwork before smashing the ball past Mainz goalkeeper Robin Zentner. Goretzka played an unlucky part in the Mainz goal when a header by defender Jeremiah St Juste cannoned off the back of his head and beat Bayern goalkeeper Manuel Neuer on the stroke of half-time. Fifth-placed Bayer Leverkusen lost ground as they went down 2-1 at Hoffenheim thanks to goals from striker Andrej Kramaric and Danish defender Robert Skov. A Timothy Chandler header just before the final whistle rescued a point for Eintracht Frankfurt in their 1-1 draw at Fortuna Duesseldorf, who moved off the bottom. It was Fortuna's first game under new coach Uwe Roesler, after the former Manchester City striker took charge on Wednesday in a bid to avoid relegation. Augsburg went ninth after they came from behind to beat Werder Bremen 2-1 with goals by Florian Niederlechner and Ruben Vargas after Tin Jedvaj had scored an early own goal. Haaland has scored seven goals in his first three Bundesliga games Mueller celebrates scoring in the 3-1 win at Mainz