Craig Burley breaks down how Unai Emery adjusted his Arsenal side to nullify Maurizio Sarri's rigid tactics for Chelsea. Alexandre Lacazette and Laurent Koscielny scored to give Arsenal a massive London derby win over Chelsea to close the top-four gap to three points. Alexandre Lacazette and Laurent Koscielny scored to give Arsenal a massive London derby win over Chelsea to close the top-four gap to three points.