Fans on Twitter exploded as Paris Saint-Germain (PSG) suffered a 1-0 defeat to Bayern Munich despite Lionel Messi, Neymar starting and Kylian Mbappe coming on as a substitute. The first leg of the UEFA Champions League round of 16 clash took place at the Parc des Princes.The Parisians failed to provide any substantial attacking threat to the Bavarians. While Messi tried a few of his signature darting runs, the final product remained missing.Warren Zaire-Emery, who made history by becoming the youngest player ever in the UEFA Champions League knockout stages, was a livewire before being replaced by Fabian Ruiz. The 16-year-old even set Neymar up after getting past Alphonso Davies. The Brazilian superstar, however, was well-marked.Kingsley Coman broke the deadlock in the 63rd minute. Alphonso Davies found the Frenchman at the back post with an immaculate cross. Coman produced a first-time volleyed finish past Gianluigi Donnarumma. The Italian custodian, however, could perhaps have done better. Coman's finish, though, deserved plaudits as he scored against his former club.Mbappe's introduction turned the tide in Christophe Galtier's team's favor. Bayern looked defensively vulnerable throughout. While the 2022 FIFA World Cup golden boot winner found the back of the net, his effort was ruled offside.Just when it looked like the French number 7 has finally found the equalizer, Nuno Mendes was ruled offside in the build-up to the goal.Messi couldn't quite make a significant impact on proceedings. Central defender Marquinhos came close with a headed effort.Benjamin Pavard was sent off after getting a second yellow for his challenge on Messi during injury time.Here are some of the best reactions across Twitter after PSG and Bayern Munich's UEFA Champions League first leg showdown:.@prime_jordan1Kids in 2050 gonna ask how Mbappe fumbled a UCL with Neymar Messi and Ramos523Kids in 2050 gonna ask how Mbappe fumbled a UCL with Neymar Messi and Ramos https://t.co/98ZWgFX8wsFaysal@elfayz_A 25% Mbappe is better than Neymar and Messi. Mental769A 25% Mbappe is better than Neymar and Messi. Mentalye@jazzronaldoLeo Messi • Best SKILLS & HIGHLIGHTS vs Bayern • The GOAT 161Leo Messi • Best SKILLS & HIGHLIGHTS vs Bayern • The GOAT 🐐🔥💣⚽️ https://t.co/kvkKTFhfETESPN FC@ESPNFCJamal Musiala got to play against his idol and role model growing up: Lionel Messi 2014121Jamal Musiala got to play against his idol and role model growing up: Lionel Messi ✨ https://t.co/3iCb89zWePESPN FC@ESPNFCLionel Messi made his Champions League debut in 2004. Warren Zaïre-Emery was born in 2006.Today, they start together against Bayern Munich. WILD! 6976349Lionel Messi made his Champions League debut in 2004. Warren Zaïre-Emery was born in 2006.Today, they start together against Bayern Munich. WILD! 😳 https://t.co/dOwnD8C6ZALiveScore@livescoreLionel Messi made his #UCL debut before Warren Zaire-Emery was born 🤯They start alongside each other against Bayern 🤝42030Lionel Messi made his #UCL debut before Warren Zaire-Emery was born 🤯They start alongside each other against Bayern 🤝 https://t.co/wWfNWhIEW8Messi Media@LeoMessiMediaMessi dribbling like he is 20 again 1874215Messi dribbling like he is 20 again 🔥 https://t.co/fM6T8eYWNrًEl.@UtdEIIisGOAT sponsoring PSG with Messi playing is so fitting.183972GOAT sponsoring PSG with Messi playing is so fitting. https://t.co/MxfwuxRyJKLeo🇮🇹- Fan@Vettel_AMRMessi when Fifa isn’t corrupting the games:63465Messi when Fifa isn’t corrupting the games: https://t.co/9onQtX2J6Sganesh🇦🇷@breathMessi21Nah Messi deserves better2127130Nah Messi deserves better😭😭 https://t.co/gh5PfiGAyn~@mercyl4sMessi and Neymar fans trying to remember when's the last time they both stepped up in a big UCL nightTwo hideous twins. 13227Messi and Neymar fans trying to remember when's the last time they both stepped up in a big UCL nightTwo hideous twins. https://t.co/73rtbw5RcvESPN FC@ESPNFCThis save from Sommer on Mbappe 71964This save from Sommer on Mbappe 😬 https://t.co/IoGn5rEycTGet French Football News@GFFNWhen he is simply so unstoppable, regardless of the disallowed goal, can we really blame PSG & France from becoming Kylian Mbappé dependent? Where is the motivation to not form all move construction around his runs? Obviously creates problems when he’s injured…235When he is simply so unstoppable, regardless of the disallowed goal, can we really blame PSG & France from becoming Kylian Mbappé dependent? Where is the motivation to not form all move construction around his runs? Obviously creates problems when he’s injured…Soccer Memes@SoccerMemesMbappe coming on like2Mbappe coming on like https://t.co/ckjVAynGLfTS🍇🇧🇷@TrujistaSanchoMBAPPE IS HIMMMMMMMMMMM HES THE BEST IN THE WORLD FFSSSSSS20611MBAPPE IS HIMMMMMMMMMMM HES THE BEST IN THE WORLD FFSSSSSSsaf@44IewisKYLIAN MBAPPE IS THAT MAN5KYLIAN MBAPPE IS THAT MAN https://t.co/Q4mAcCEJDtRonan Murphy@swearimnotpaulMbappe is so good. Even half fit, he’s better than everyone else. #PSGFCB273Mbappe is so good. Even half fit, he’s better than everyone else. #PSGFCBJulie Stewart-Binks@JSB_TVMBAPPE WITH TWO OFFSIDE GOALS 81MBAPPE WITH TWO OFFSIDE GOALS 😱😱😱ℂ𝔸𝕊𝔸𝔻𝔼𝔹𝔸ℕ𝕋𝔸™️😆@casa_de_bantaMbappe seeing all the open spaces in the Bayern defence #PSGFCB99792Mbappe seeing all the open spaces in the Bayern defence #PSGFCB https://t.co/7KAmv6v1maMbappe Out Of Context 🇫🇷@MbappeOOC288https://t.co/DwtSPhI41z💎🇶🇦@TJayyyy_1no cap whenever my dad sees neymar lose the ball carelessly he’s literally like this to me856no cap whenever my dad sees neymar lose the ball carelessly he’s literally like this to me💀 https://t.co/U1dqOMvEepJohn H O N E S T Y@ExJohnHonestyyThe jersey Neymar Junior wore the last time he performed in a game that actually matters969The jersey Neymar Junior wore the last time he performed in a game that actually matters https://t.co/iQFqSVu3EpPSG Report@PSG_ReportMBAPPE NEYMAR NOOOO WHAT A CHANCEEEEMBAPPE SCORES BUT OFFISDE!!!! 26716MBAPPE NEYMAR NOOOO WHAT A CHANCEEEEMBAPPE SCORES BUT OFFISDE!!!! ❌❌sakib 🇵🇰@sakib_lfcNeymar after stinking the pitch watching Mbappe do all the work after coming on as a sub61Neymar after stinking the pitch watching Mbappe do all the work after coming on as a subhttps://t.co/AL6wgcgd0f⚡️@clinicalkaiMessi and Neymar today11519Messi and Neymar today https://t.co/O0owZmKgTUℂ𝔸𝕊𝔸𝔻𝔼𝔹𝔸ℕ𝕋𝔸™️😆@casa_de_bantaMessi & Neymar tonight #PSGFCB11Messi & Neymar tonight #PSGFCB https://t.co/Fc5XRGIs38PSG remain unconvincing in the UEFA Champions League despite Lionel Messi, Neymar and Kylian Mbappe's presencePSG v Manchester City: Group A - UEFA Champions LeagueDespite Lionel Messi, Neymar and Kylian Mbappe's presence, PSG's performances in the UEFA Champions League leave a lot to be desired for.Last season, they were knocked out by Real Madrid in the round of 16 of the tournament. Christophe Galtier's team finished second in their group this season, behind Benfica.Now, they might be looking at elimination in the round of 16 again. A remarkable turnaround in form is needed if they are to proceed to the quarter-finals.