Championship side Derby County pulled a stunning upset by beating Manchester United 8-7 on penalties in the EFL Cup. Juan Mata gave the Red Devils a lead with a brilliant finish in the 3rd minute of the game before Liverpool's loanee, Harry Wilson, equalised for the Rams with a stunning free-kick in the second half. Jack Marriott thought he had won it for the Derby with his goal in the 85th minute, but Marouane Fellaini forced the game into the extra time scoring by deep in injury time.As extra time is no longer played in the early rounds of the EFL Cup, the game went straight to penalties. Both teams were faultless from the spot, before Scott Carson saved from Phil Jones, sending the Rams through to the next round of the competition.Manchester United have had a tough start to the season and this defeat will increase the pressure on Jose Mourinho. The Portuguese manager looked frustrated after the game, and criticised his team's attitude as they threw away a lead for the second consecutive match The Reds Devils finished second last season, but are on the seventh place in the Premier League table, eight points behind leaders Liverpool.Jose Mourinho criticised the board for not providing him with a sufficient amount of funds to spend in the transfer market, and the big-name players like Paul Pogba and Alexis Sanchez are struggling to perform as well.Derby County are sixth in the Championship, and are among the favorites to promoted to the Premier League this season, having missed out in the play-offs last year.Twitter reacted to Manchester United's defeat, and here are some of the best tweets.Manchester United mood. pic.twitter.com/JBfgCm3SFp— B/R Football (@brfootball) September 25, 2018“Is he (Mourinho) the right fit for @ManUtd? I don’t think he is,” Jamie Redknapp.— Jim White (@JimWhite) September 25, 2018This is shameful day in Manchester United's history just like last year v Bristol City 😐😔— 🇬🇧🇲🇽 Yulissa Low (@YuliLow) September 25, 2018Just bring on Mourihno and Manchester United😅😅😅 WE ARE READY🤣🤣🤣 pic.twitter.com/E84j5OyKlY— Natugumya Obed (@Obed_taka) September 25, 2018Manchester United is the new Arsenal— Anda (@LazyWrita) September 25, 2018From the start of Pre season, Mourinho has had a bad attitude. Falling out with all our players, terrible standard of football, he has quickly turned @ManUtd into a laughing stock of football. Thank you Jose for destroying my club. Now please leave #mufc— Andreas Valera (@AndreasValera) September 25, 2018Manchester United have been knocked out of the League Cup by lower league opposition in 4 of the last 5 seasons.— Sibs 🐝🔰 (@SibsMUFC) September 25, 2018Losing to a Championship side is bad enough, but to go out on a whimper and play absolutely shocking football is completely inexcusable. Manchester United are a shadow of its former self.— Liam Canning (@LiamPaulCanning) September 25, 2018Oh my God! Manchester United got bundled out of Carabao Cup in the 3rd Round at Old Trafford. To make matters worse it was against Frank Lampard's Derby County (Championship Side). So Old Trafford no longer has fear factor? #Feelingsad #Whataweek— Oluwaseun Ajidagba (@seunajidagba) September 25, 2018No team out there, no matter how big or small, is going to be worried about taking on Manchester United. The aura has well and truly gone, as well as Old Trafford being a fortress. Any club will feel confident in beating this lot.— Liam Canning (@LiamPaulCanning) September 25, 2018Still better than the current Manchester United side. 👊☠ pic.twitter.com/aGfeasV5gg— Football Tweet (@Football__Tweet) September 25, 2018We’re getting outplayed by Wolves and Derby at Old Trafford! It looks like the Manchester United players are scared to play at Old Trafford than the opponents! #MUFC— Manchester United (@MUFCScoop) September 25, 2018