Real Madrid roared back from two goals down to thump Borussia Dortmund 5-2 at the Bernabeu as Vinicius Junior grabbed a hat-trick.
Holders Real were on course for a second defeat in three matches in this term's league phase, having lost 1-0 at Lille last time out, after Donyell Malen and 20-year-old Englishman Jamie Bynoe-Gittens scored for Dortmund in the 30th and 34th minute respectively.
But Carlo Ancelotti's men, who had hit the bar twice shortly after Bynoe-Gittens' goal, subsequently produced a ruthless second-half response, starting with Antonio Rudiger's header halving the deficit on the hour mark and Vinicius Junior equalising two minutes later.
Lucas Vazquez then put them in front in the 83rd minute before Vinicius Junior added two further strikes to claim the match ball.
Aston Villa made it three wins from three as goals from John McGinn and Jhon Duran gave them a 2-0 home victory over Bologna.
Arsenal are also unbeaten, with seven points, after defeating Shakhtar Donetsk 1-0 at the Emirates Stadium courtesy of an own goal, Gabriel Martinelli's first-half strike rebounding in off goalkeeper Dmytro Riznyk.
Paris St Germain drew 1-1 at home with PSV Eindhoven, Achraf Hakimi's effort for the French champions cancelling out Noa Lang's opener.
Juventus suffered a 1-0 defeat to Stuttgart after a dramatic conclusion at the Allianz Stadium.
A foul by Danilo on Anthony Rouault led to the Juve man being sent off and the visitors being awarded an 86th-minute penalty, which went unconverted as Enzo Millot's effort was saved by Mattia Perin, before El Bilal Toure secured victory for Stuttgart in stoppage time.
AC Milan saw off 10-man Club Brugge 3-1 at the San Siro, with Tijjani Reijnders notching a brace.
After Christian Pulisic put Milan in front, Brugge had Raphael Nwadike sent off in the 40th minute, only to equalise through Kyriani Sabbe early in the second half. Reijnders subsequently netted twice to hand the hosts three points.
Takumi Minamino scored twice as Monaco thrashed Red Star Belgrade 5-1 at home and there were 2-0 wins for Girona at home against Slovan Bratislava and Sporting Lisbon at Sturm Graz.
