Not long ago, one of two teams on the pitch today was running away with the Premier League title while the other was embroiled in a relegation dogfight. Coming into the match today, few had given the Lancashire-based club an ounce of chance against the defending champions. However, what transpired over the course of 90 minutes outdistanced everyone's predictions as Burnley held on against a nine-man Chelsea to take home three invaluable points.3 - Chelsea are the first reigning Premier League champions to concede three goals in their opening match of the next season. Collapse.— OptaJoe (@OptaJoe) August 12, 2017Following Gary Cahill's red card in the 14th minute of the match, Sean Dyche's men raced to a three-goal lead in the first half. With pride at stake, Chelsea came out in the second half firing on all cylinders as debutant Alvaro Morata's goal reduced the deficit. Although Cesc Fabregas's sending off further dented their chances of making a comeback, David Luiz scored in the dying embers of the match to ensure a frantic finale.Here are five of the various talking points from the match.#1 Cahill's red card sets the tone of the matchIf there are a '101 ways of commencing a title defence', this, here, certainly wasn't one of them. Chelsea's skipper, while making inroads into the Burnley half, lost control of the ball, and went for a studs-up lunge on Steven Defour. The referee was in a great position to spot the challenge and off went Cahill.Here, Dyche's team need to be credited as they made full use of the numerical advantage, dominated possession and banged in three goals in the first half itself to all but end Chelsea's chances of staging a comeback. Sam Vokes scored on either side of a perfect Stephen Ward volley.1 - Chelsea had gone 40 successive Premier League matches without a red card (since May 2015) before Gary Cahill's dismissal today. Off.— OptaJoe (@OptaJoe) August 12, 2017Chelsea's stalwarts weren't done yet as after a booking in the first half, Fabregas picked up his second yellow late in the 80th minute while Morata was leading Blues' charge.2 - Chelsea have been given two red cards in the same Premier League game for the first time since March 2014 (vs Aston Villa). Anger.— OptaJoe (@OptaJoe) August 12, 2017Though Cahill's red was a big blow for the team as a whole, it must've been disheartening for Jeremie Boga, a Chelsea academy product, who was making his debut, to get substituted within 18 minutes to allow Andreas Christensen fill in for the skipper.Jeremie Boga completed 4 passes before being subbed after 18 minutes into his Premier League debut.Seriously unlucky not to get a chance. pic.twitter.com/CZCVXuR9zA— Squawka Football (@Squawka) August 12, 2017