The loss was largely self-inflicted as mistakes from Laurent Koscielny and Shkodran Mustafi proved costly in the opening 11 minutes before David De Gea made a series of fine saves to frustrate the hosts.
"If it was hard, no; if it was mud, no - the pitch is absolutely lovely but I think they were a bit too much".
"I think it was a fantastic game", Mourinho, whose United sides had managed only one goal in their previous seven aways to Manchester City, Liverpool, Arsenal, Tottenham Hotspur and Chelsea, told reporters.
Pogba is likely to feature on Tuesday night when United will seek to secure their place in the Champions League knockout stages against CSKA Moscow.
Asked if United's fourth successive league win had sent a message to Pep Guardiola's team, he said: "No message".
And Wenger feels his players deserved more from the game. "Arsenal played in some period wonderful attacking football - creating difficulties for us".
Inevitably, Arsenal boss Arsene Wenger saw the two penalty appeals differently to his old rival and he took a swipe at Marriner's performance.
Antonio Valencia and Jesse Lingard punished bad Arsenal defending to put United two up in 11 minutes.
"At the beginning we needed to be patient with Brighton's style, " said manager Jurgen Klopp, whose side have scored 12 goals in their past three Premier League away games."We needed to get used to it".
"You have to dictate from the start and show strength in duels from the back", Wenger said. Son Heung-Min equalised midway through the first half but Spurs were reduced to 10 men when Davinson Sanchez was dismissed shortly after the restart. "We defended very well, I don't think they created many chances after that, so the three points stayed with us".