Manchester City moved to within three points of Premier League 2 leaders Everton with a 3-0 victory at the Academy Stadium.
Substitute Thierry Ambrose and attackers Jadon Sancho netted for the Blues in the second half to keep their title hopes alive.
Diaz was the first to get the crowd off the seat of their pants when he wriggled inside and curled an effort, only to see it diverted wide by Mateusz Hewelt’s big toe.
The Spaniard appeared to be City’s biggest threat throughout the first half but his hustling bore little fruit against a compact Everton defence.
In fact, much of the first half was defined by the different set-ups of both sides. Everton pressed City high, forcing them to play the ball longer than usual but once through, City would often be in a dangerous position.
Goalless at half-time, City came out determined in the second period to lessen the gap at the top of the table. However, early chances for Tosin Adarabioyo and Sancho came to nothing and City were still searching for the opener as the hour mark approached.
Ambrose's introduction gave Simon Davies' side a focal point and allowed Diaz to move into a more creative midfield role. It paid dividends almost immediately as the striker collected the ball inside the box, shifted into a yard of space and drilled an effort inside the near post.
Diaz doubled City's lead just six minutes later following a long period of City pressure. Everton blocked the efforts of both Ambrose and Paolo Fernandes before Diaz's shot found its way through. City weren't done there though.
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