Rival fans have taken to social media to express their delight as Manchester United trail Brighton & Hove Albion in their season opener.Manchester United have tasked Erik ten Hag with taking them back to the top this season. They have also backed the Dutchman in the transfer market, bringing in Lisandro Martinez, Tyrell Malacia and Christen Eriksen.The Red Devils thus went into their Premier League opener against Brighton at Old Trafford with high hopes. However, the hosts have struggled to hit the ground running under their new manager thus far.Ten Hag and Co. currently find themselves trailing 2-0 against Brighton at home. Despite dominating possession, they have only managed to test Seagulls goalkeeper Robert Sanchez on two occasions.Pascal Gross opened the scoring for Graham Potter's side in the 30th minute of the match. The German combined with former Manchester United forward Danny Welbeck to stun the hosts.The 31-year-old went on to score his second of the afternoon and double Brighton's lead just nine minutes later. David de Gea failed to hold on to Solly March's shot and Gross lashed the rebound into the top right corner.Ten Hag's side thus had a calamitous first half against Brighton and have a task in hand to turn things around in the second half. Rival fans, though, appear to have enjoyed Manchester United's struggles in the first 45 minutes of the game.¹⁰@SxrgioSZNTen Hag coming to end the Klopp and Pep era they said 🥶🥶3713265Ten Hag coming to end the Klopp and Pep era they said 🥶🥶Laurie@LFCLaurieErik Ten Hag | Tactics and Philosophy | The Man to Save Manchester United 25725Erik Ten Hag | Tactics and Philosophy | The Man to Save Manchester United 🔥 https://t.co/P6TKF8SI0sZubin Daver@zubinofficialErik Ten Hag after 45 minutes of football as Manchester United manager17831Erik Ten Hag after 45 minutes of football as Manchester United manager https://t.co/26cqulFZMMSripad@falsewingerErik ten Hag is writing something on the touchline.Bit too early for it to be a resignation letter, I guess?526Erik ten Hag is writing something on the touchline.Bit too early for it to be a resignation letter, I guess?Samuel@SamueILFCWelcome to United, Ten Hag 1638123Welcome to United, Ten Hag 😂😂😂Erling Haaland@SulaimanAtiku6Welcome to the Premier League, Erik ten Hag.#MUNBHA #MUFC1Welcome to the Premier League, Erik ten Hag.#MUNBHA #MUFCV@itsthemchasers@ivan_i94 Führer Rangnick >> Erik Ten months@ivan_i94 Führer Rangnick >> Erik Ten monthsManchester United pull one back against BrightonThe Red Devils have managed to pull one back against Brighton in the second half. An own goal from Seagulls midfielder Alexis Mac Allister following a corner in the 68th minute has given the hosts hope.Meanwhile, Ten Hag has also brought on Cristiano Ronaldo as a substitute with the hope of turning things around. Donny van de Beek has also replaced Scott McTominay in midfield.It now remains to be seen if the Old Trafford outfit can bring the match back to square one with another goal. Ten Hag will be keen to avoid defeat in his first competitive game as Red Devils manager.