Liverpool became the first English team to reach the quarterfinals stage of the UEFA Champions League 2017/18 after a goalless second leg draw with Porto at Anfield. The first leg 5-0 demolition of Porto was enough to advance them into the last eight, and they have currently been joined by two-time defending champions Real Madrid.With an upcoming visit to Old Trafford this weekend for a match against Manchester United, which could have major implications on who finishes second in the Premier League this season, Liverpool manager Jurgen Klopp rang in quite a few changes - especially benching the man in form, Mo Salah. FC Porto were happy to reciprocate as well, as they made 10 changes to the team that played in the first leg.Salah would eventually come on in the 74th minute but he was unable to continue the goalscoring streak as the last 15 odd minutes weren't enough for him to give Liverpool a victory in the second leg as well.While this match wasn't entertaining and didn't really capture how a Champions League knockout match feels like, there was a landmark event as Liverpool qualified for the Champions League quarterfinals for the first time in 9 years. The 5-time winners had last advanced to the quarterfinals in the 2008/09 season after defeating Los Blancos 5-0 over aggregate, but were then knocked out after domestic rivals Chelsea defeated them 7-5 over the two legs.This match could also mark the last time we have seen Iker Casillas in a Champions League game. There are rumours that he could be released by Porto at the end of the season, and at 37 years of age, it could be difficult for him to find a starting berth at a club challenging in the European competitions.Twitter reacted to Liverpool's progression and here are some of the best tweets:Every time a player goes to tackle Salah in the last 10 mins...#LIVPOR #LFC #YNWA #MUNLIV pic.twitter.com/on54gAMpI1— Samantha Quek (@SamanthaQuek) March 6, 2018😏 The only teams still unbeaten in the Champions League…- Liverpool- Barcelona- TottenhamNot bad for a team with Lovren in defence#LIVPOR pic.twitter.com/Tont4lEId9— The Sportsman (@TheSportsman) March 6, 2018After 6 years with Arsenal Oxlade-Chamberlain finally makes it to the UCL Quarterfinals with Liverpool in just 6 months: 👏👏2012 - Lost to Milan2013 - Lost to Bayern2014 - Lost to Bayern2015 - Lost to Monaco2016 - Lost to Barcelona2017 - Lost to Bayern2018 - Win v Porto pic.twitter.com/B94qIF3c4s— Football Stuff (@FootbalIStuff) March 6, 2018Barcelona, Real Madrid, Liverpool, Manchester United and Bayern Munich will always remain the kings of football. No matter how much teams like PSG spend, they'll forever remain small and shit.— Messi World (@MessiWorId) March 6, 2018Liverpool’s 🔥 front three are moving on up in the Champions League pic.twitter.com/bhQCStfWT0— B/R Football (@brfootball) March 7, 2018Some might think that beating Dortmund 4-3 at Anfield was my favourite game in a Liverpool shirt, but that 0-0 draw against Porto just pips it. It had everything.— Boring James Milner (@BoringMilner) March 6, 2018Quite fancy City-RM and Liverpool-Barça* next (*if they get through)— Sid Lowe (@sidlowe) March 6, 2018Europa League 2010-11, Liverpool knocked out by a single goal (over two-legs) in the round of 16 by Braga.Champions League 2017-18, Liverpool sail through to the quarter-finals after beating Porto 5-0 on aggregate....You see the difference?Don’t moan.— Ben Webb (@BenWebbLFC) March 6, 2018Liverpool have now kept 5 clean sheets in the last 7 games in all competitions 👌🏻 pic.twitter.com/hZPiOdaGch— LFC Stats (@LFCData) March 6, 2018Liverpool saving all their goals for Utd #LIVPOR pic.twitter.com/h5fErNHTF2— Givin It Bifters (@ThisKop) March 6, 2018