Teenager Marcus Rashford scored twice and set up the third as Manchester United derailed Arsenal’s Premier League title challenge at Old Trafford. Rashford, who scored twice on his debut against FC Midtjylland on Thursday, steered in a loose ball for the opener then headed in three minutes later. Danny Welbeck nodded Arsenal back into the game, but Rashford picked out Ander Herrera whose shot was deflected in. Mesut Ozil’s volley gave third-placed Arsenal hope, but United held on. Arsenal – who have not won the title since 2004 – remain in third place, five points adrift of leaders Leicester having now played the same number of matches.

The Red Devils moved back into fifth position with their first win in three league games. With leaders Leicester snatching a late win on Saturday, and second-placed Tottenham fighting back against Swansea, Arsene Wenger’s side lost valuable ground on their title rivals. And it ended a miserable week for the Frenchman, who saw his side falter in three competitions. Wenger watched his team labour to an FA Cup draw against Championship side Hull, then put themselves on the brink of a Champions League exit at the hands of Barcelona. “This is a fight where you keep going even when disappointment is there. Let’s show we are prepared for the fight,” he said.

Arsenal have not enjoyed their Premier League visits to Old Trafford in recent seasons, failing to pick up three points there since September 2006. And many felt the Gunners needed to finally win at Old Trafford if they are going to end an even longer barren run – becoming the English champions. The opportunity to beat United was probably the easiest for Arsenal than any other time during Arsene Wenger’s 20-year reign. But their defensive errors cost them dearly. “I cannot fault the commitment and desire but unfortunately we conceded two easy goals,” said Wenger afterwards.

Really? The manager & club are perfect for each other, lacking passion and commitment to winning the league. Can we please now throw that moron Arsehole Wenger outta this club he has fucked up? I think it’s time to look at the squad hard and long and chuck out a few players. And that manager! A big fuck you to Arsehole Wenger. Get the fuck outta our club!

Lionel Messi effectively condemned Arsenal to a sixth successive exit at the last-16 stage of the Champions League with two decisive goals at Emirates Stadium. Arsenal battled gallantly to give themselves a chance going into the second leg at the Nou Camp in three weeks’ time – but suffered at the hands of Barcelona’s superstar trio Messi, Neymar and Luis Suarez. After Alex Oxlade-Chamberlain and Olivier Giroud had come close to giving Arsenal the lead, Messi scored his first goal against keeper Petr Cech at the seventh attempt when he crowned a blistering counter-attack involving Suarez and Neymar to sweep home a finish after 71 minutes.

And further damage was inflicted seven minutes from time when Arsenal substitute Mathieu Flamini floored Messi with a mistimed challenge and he got up to send Cech the wrong way from the spot. It was his eighth goal against Arsenal in the Champions League. Suarez hit the post and Cech saved from Neymar as Barcelona took control – but this tie already looks well out of Arsenal’s reach. Arsenal went out to Barcelona in 2010 and 2011 and that was after a draw and a win at Emirates Stadium – so their chances can be all but written off after this defeat. The Gunners had their chances but they came to nothing, with Oxlade-Chamberlain a culprit when he allowed Barcelona keeper Marc-Andre ter Stegen to save from a huge opportunity before Giroud saw a second-half header well saved. Such is the ruthlessness of this Barcelona side that even half-chances (or less) have to be accepted and, if they are not, there is almost an inevitability about the outcome.

Wenger can make the usual optimistic noises about the second leg in the Nou Camp but it would be the greatest result of his reign if he managed to inspire a turnaround from this position. It is, perhaps, on nights like these that those calls for Wenger to sign a world-class striker carry greater resonance because even the smallest opportunities have to count and Arsenal were unable to do so. Arsenal and manager Wenger will be desolate after this result effectively consigns them to yet another last 16 exit – but they deserve a measure of credit for their display. In the first half they were hugely disciplined to keep Barcelona at bay, indeed in the first 30 minutes the holders only had two touches in Arsenal’s penalty area compared to 11 from Wenger’s team. Goalkeeper Cech was immense while Nacho Monreal and Aaron Ramsey were also excellent. Ultimately, however, Arsenal were not good enough – no shame in that – but all that is left is for Barcelona to complete the formalities in Catalonia in three weeks.

Arsenal must travel to Hull for an FA Cup fifth-round replay after failing to turn dominance into victory against the Championship leaders. The Gunners had two penalty claims denied and had chances to win the game through Theo Walcott and Danny Welbeck. Hull keeper Eldin Jakupovic made a string of saves, most notably touching Joel Campbell’s free-kick on to a post. The Tigers created little, but defended admirably to frustrate Arsene Wenger in his 100th FA Cup game as Arsenal boss. The two sides made a total of 19 changes between them from their previous games – nine for Arsenal and 10 for Hull. But Steve Bruce’s Tigers not only ended a 14-game winning run in the FA Cup for the Gunners, they also prevented a repeat of their defeats by the Londoners in the 2014 final and last season’s third round.

Arsenal’s priorities undoubtedly lie elsewhere, with Wenger’s side only two points off the top of the Premier League and a visit of Barcelona in the first leg of their Champions League last-16 tie coming up on Tuesday. Europe is particularly pressing for the Gunners, who have failed to go past the last 16 in any of the past five seasons, which meant there was no place for key man Mesut Ozil in the squad, while Olivier Giroud and Alexis Sanchez were restricted to contributions from the bench. Despite the team bearing little resemblance to the XI that started in the 2-1 win over Leicester City last week, the Gunners were good enough to control the game from start to finish and created enough chances to have secured a comfortable victory. However, the draw means Arsenal are still in with a chance of becoming the first team to win three consecutive FA Cups since Blackburn Rovers accomplished the feat 130 years ago.

Arsenal’s only issue came in front of goal, as they moved the ball around with precision to carve out 24 shots – 11 on target – compared to the six shots mustered by Hull. But they could not find a way past Jakupovic, who allowed himself a self-congratulatory moment after taking time out to watch a replay of one of his saves on the big screen at the Emirates. January signing Elneny, making only his second start for the Gunners, put in a standout performance for the home side. The Egypt international was always available for the ball in midfield and dictated the pace for Arsenal from the middle of the park. And there were promising signs from 19-year-old Nigerian Iwobi, who found plenty of space behind striker Theo Walcott to attempt through balls into a congested Hull penalty area, only for the hosts to draw a blank every time.