With Jose Mourinho watching from the stands, Hertha Berlin held league top-scorer Borussia Dortmund to 0-0 in the Bundesliga on Saturday.
Mourinho was a guest of Dortmund chief executive Hans-Joachim Watzke, whose team was frustrated for long periods by the home side.
Hertha might have gone ahead in the first half when defender John Anthony Brooks headed narrowly over from a corner.
Dortmund sent on attacking midfielder Christian Pulisic for his second Bundesliga appearance, but needed a last-ditch tackle from Sokratis to safeguard the draw.
Elsewhere, Schalke defeated Wolfsburg 3-0, Stuttgart won at Eintracht Frankfurt 4-2, Ingolstadt defeated Augsburg 2-1, and Mainz won at Hannover 1-0.
Bayern Munich visited Bayer Leverkusen in the late game. Bayern had the chance to go 10 points clear.
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