Jose Mourinho took another swipe at Arsene Wenger by insisting the Frenchman's poor record against him is "not normal" after Arsenal's 2-0 victory over Manchester United.
Wenger celebrated his first Premier League win over Mourinho at the 13th attempt after goals from Granit Xhaka and Danny Welbeck kept Arsenal's Champions League qualification hopes alive.
Mourinho said defeat meant it would now be "impossible" for United to finish in the top four, insisting his team's chances of playing in Europe's premier competition next season now rest entirely on winning the Europa League.
Eight changes to United's starting line-up at Emirates Stadium certainly pointed to Mourinho's focus on Thursday's semi-final at home to Celta Vigo, where they hold a 1-0 advantage from the first leg.
But while United chase their second major trophy this term, the Portugese could not resist another dig at Wenger's lack of success in recent years.
Asked about Arsenal finally tasting victory against him, Mourinho said: "It's a big club. You think I enjoy a big club like Arsenal not winning big trophies? I am not enjoying that honestly.
"But today I tried to win. I didn't give them the match, I tried to win but we lost. Arsene Wenger is not a small manager, he is a big manager so to have that record of winning so many matches and losing so many matches is something that is not normal. That is not normal.
"Normal is win, lose, draw. It's not normal and I really don't care about it. Today no problem - we shook hands before the game, we shook hands after the game.
"And during the game I didn't like what I never like, he puts too much pressure on the fourth official all the time."
Arsenal fans taunted Mourinho in the latter stages of their victory, which puts the Gunners six points behind Manchester City, with one game in hand, and seven back on Liverpool, having played two games fewer than the Reds.
"The Arsenal fans, they are happy," Mourinho said.
"I am happy for them, it is the first time I leave Highbury or Emirates and they are happy. I left Highbury, they were crying, I left Emirates, they were crying.
"They were walking the streets with their heads low. So finally today they sing, they (swing) the scarves - it's nice for them."
United, meanwhile, now sit four points behind City and five adrift of Liverpool, with only one game in hand over Jurgen Klopp's men, and a tricky trip to Tottenham to come next weekend.
It means their chances of sneaking into the top four would appear increasingly remote.
"It's impossible," Mourinho said. "For two reasons: I don't think the other ones playing one match a week and being in a great situation, I don't think they are going to blow it.
"And because we go with everything on Thursday and we cannot go with everything against Tottenham. When you go with everything against Tottenham it's difficult. When you don't go with everything it's more difficult.
"Two days later Southampton, two days later Crystal Palace. This is too much for us so I don't think we have any chance of finishing top four in the Premier League.
"We have to chase Champions League by trying to win the Europa League."
Manchester United boss Jose Mourinho hailed the return of injured trio Chris Smalling, Phil Jones and Juan Mata, with the defensive duo lasting 90 minutes and playmaker Mata coming off with five minutes left.
"(Arsenal) had a bit of luck with their first goal," Mourinho said.
"I cannot demand any more from players who have played not one minute of football in the last seven weeks.
"I think Jones, Smalling and Mata were amazing the way they performed after seven weeks of being out."
Mourinho was also fulsome in his praise for young defender Axel Tuanzebe, who was handed his Premier League debut.
"I think he did an amazing job and I think Alexis (Sanchez) knows his name because the kid has played really well and other players were trying to do everything," the Portuguese added.
Wenger, who finally got the better of old adversary Mourinho in the Premier League, admits qualifying for the Champions League remains a long shot but said: "There's still a mathematical chance.
"We need some help but the best help we can get is from our own focus between now and the end of the season."
Arsenal striker Danny Welbeck was delighted to score his fourth goal of an injury-ravaged season, despite his second-half header helping to down his former club Manchester United.