Birmingham - Louis van Gaal fears Manchester United's failure to beat Aston Villa will prove a major blow to their hopes of winning the Premier League title.
United's slim chance of reviving their bid to become English champions suffered a setback on Saturday as they were forced to settle for a 1-1 draw at 10-man Aston Villa.
Radamel Falcao's first goal since October 5 cancelled out Christian Benteke's fine opener for Villa, yet the contest was later overshadowed by referee Lee Mason's controversial dismissal of Gabriel Agbonlahor for a seemingly innocuous challenge on former Villa team-mate Ashley Young.
It ended United's run of six successive victories as they lost ground on rivals Manchester City, who had earlier moved level on points with leaders Chelsea ahead of their trip to Stoke on Monday.
It leaves the gap between those two and United, who sit third, at seven points.
Asked if that this was the sort of result that can cost you the title, he replied: "Yes, that's what I mean. We dropped two points.
"We were the better team and that is frustrating when you are the better team and you don't win these kind of games.
"When you want to be a part of the title race you have to win these games.
"I have seen Manchester City's first half against Crystal Palace and they could have been behind in the first five or 10 minutes.
"They struggled until half time but at the end it is 3-0, that's the difference.
"We weren't so aggressive in the first half as we are usually. We kept the ball much better but didn't create so much because we were not looking for the forwards.
"We have a draw and that's why I'm a little frustrated because you could have won the game in my opinion. We didn't do it but we were responsible for that."
United adopted van Gaal's favoured back three in the first half -- before he changed after the interval -- yet tactically Villa had the better shape and were always a threat with the counter-attacking game which has become their trademark under boss Paul Lambert.
Little appeared on as Fabian Delph's free-kick found the former Genk player at the back post, yet he controlled superbly, twisted Jonny Evans inside out and bent a shot superbly inside the left post.
United finally grew into the game after the break and Villa's resistance was finally broken in the 53rd minute when Falcao emphatically buried Young's left-wing delivery with a bullet header.
"It was a beautiful goal, I liked Falcao today. I am very happy for him and I am always happy when Manchester United score," van Gaal said.
"Should he start more? I have to compare every week, there's always a question for every player, not only for Falcao."
Then came the controversy. Young and Agbonlahor hurtled towards one another as they vied for a challenge, yet it was the former who was left crumpled in a heap and Mason reacted by reaching for his red card, leaving Agbonlahor and the Villa Park crowd stunned.
"If that is a red card we may as well just pack it in as it won't be a game of football," said Lambert.
"I spoke to (Villa goalkeeper) Brad Guzan after the game. He tells me that Ashley Young has admitted he fouled 'Gabby'. Work that one out.
"There is a very good chance of us appealing. If people review that we have a chance, especially when a player has admitted he fouled 'Gabby'."