London: Manchester United manager Louis van Gaal expressed frustration after his side squandered a chance to avenge their Premier League opening day loss to Swansea City in a 2-1 defeat.
Ander Herrera gave the visitors a 28th-minute lead at the Liberty Stadium on Saturday, but Swansea equalised less than two minutes later through South Korean midfielder Ki Sung-yueng.
The game was won 17 minutes from time when Bafetimbi Gomis inadvertently deflected Jonjo Shelvey`s long-range strike over David de Gea to bring United`s 19-game unbeaten run to a halt.
"It is always frustrating when you dominate a team and lose," van Gaal told reporters after a result that saw his team slip to fourth place.
"Your disappointment is much bigger because of that. If you think they deserved to win, you have to say.
"The first half, I think, was equal. I counted the number of chances Swansea had and we had the same. We scored one each, so there was no big difference.
"In the second half, there was a big difference. But we were not effective. We dominated the game, even with 10 men, because Robin van Persie could not run anymore after his injury.
"I cannot say anything about my players except that we lost. The disappointment is much bigger. I think you have to see the slow-motion of the match, then you can see which players were not effective.
"Sometimes you can control the ball instead of shooting directly. Normally we are very effective, so it is amazing that we have lost."
Van Persie left the stadium on crutches after injuring himself late on and his striker partner Wayne Rooney admitted it had been a day to forget.
"We certainly deserved to win the game," said the United captain. "That`s the disappointing thing. When you play well and can`t get the win. But that`s football."Gomis`s fortuitous goal allowed ninth-place Swansea to complete a first ever home-and-away league double over United and victorious manager Garry Monk said he was more than satisfied with the manner of victory.
"I would rather be lucky than good," he said. "Yes, we had to ride some pressure, but even with the players they have, they only had one shot.
"We scored a very good goal in the first half and responded as you would want your players to respond. We had shots cleared off the line and we more than competed.
"I think we needed to be a bit better in the second half, but we dealt with the pressure they put on us. In the end, we scored a fantastic goal and probably could have had a third."
Monk also expressed pride in his players` reaction after a disappointing 2-0 loss at West Bromwich Albion in their previous outing.
"It is the first time in the club`s history that we have got the double against them and I told the players before the game that anything, in terms of creating history, is worth fighting for," he said.
"To be able to do the double, I think everyone connected with the club should be proud. I have always believed in my team.
"It won`t always go to plan, but we responded well after a disappointing result at West Brom. We stuck together and got the win, which our performance deserved. We have to be pleased.
"I have spoken to the group about an opportunity to create a special season. We might not be winning the league, but we have different things to fight for.
"You have to be remembered for something. We have 13 games left in our season and we have to remain focused on those games."