Bayern, the German record champions, deservedly won the Bundesliga's top match 6-1 (3-0) against an alarmingly weak RB Leipzig. The result made amends for the disappointments in Augsburg (2-2) and Stavanger (3-3).
Having faced occasional criticism recently, Díaz answered with a hat-trick for the Munich side in the 12th, 47th and 69th minutes. Bayern were superior in every respect, with Aleksandar Pavlovic (26th), Michael Olise (34th) and goalscorer Harry Kane (53rd) also finding the net. Andrija Maksimovic (90+1) scored only a consolation goal for Leipzig.
Vincent Kompany's team took plenty of confidence from the win into Wednesday's showdown against the Gunners (9pm/DAZN). They also took top spot in the table, at least until Sunday.
For RB, the debacle came in coach Martin Demichelis's second game against his former club, just before Wednesday's Champions League clash at Real Madrid (9pm). Leipzig, out of sorts throughout, never stood a chance as they suffered their third league defeat of the season.
Before the match, Kompany had stressed that his team like pressure. "The hunger has been awakened," he said. Bayern started with plenty of energy, and Kane had the first good chance as early as the second minute. They kept pressing, with Díaz left unmarked to score from a superb Joshua Kimmich pass.
RB goalkeeper Vandevoordt prevents even bigger Bayern win
Soon afterwards, RB goalkeeper Marten Vandevoordt thwarted Dayot Upamecano, one of three new faces compared with the Viking match, and Ismael Saibari. He could do nothing about Pavlovic's low shot from close range after a Díaz pass, or the lively Olise's ninth goal of the season. Vandevoordt kept the score down before the break as Munich created further chances.
At the other end, Jonas Urbig had a quiet first half. The 23-year-old again replaced the injured Manuel Neuer (40), doing so for the fourth time this season. On the touchline, assistant coach Aaron Danks repeatedly urged Munich on, as alleged hip problems limited Kompany's involvement.
Demichelis, who played 174 times for Bayern between 2003 and 2011, responded by bringing on two new players. They had barely taken the field when Díaz struck again. Kane added another, his ninth goal of the season. Careless Leipzig made life easy for Bayern, as the Colombian Díaz demonstrated once more.