Daley Blind has warned his Manchester United teammates there is still work to do to secure a place in the Europa League final.
United will take a 1-0 lead into their semifinal second leg with Celta Vigo next week after Marcus Rashford's goal in Spain.
Jose Mourinho's team were on top for much of the game and could have won by more had a series of chances been converted.
The Reds boss said afterwards the tie is still "open."
And Blind insists United will have to be at their best at Old Trafford next week to progress to the final in Stockholm on May 24.
"It's a good result," Blind told MUTV.
"We had good chances in the first half that we didn't finish. I think we're happy with the 1-0. There's a second game and 1-0 is a good result.
"We are always confident but it's still a semifinal and anything can happen. It is a good result away and we're in a good position.
"It's a great position but we have to keep in mind we have one more game to play, and play with the same attitude. We are not there yet and we have to make sure we get there."
Meanwhile, Marouane Fellaini admitted he had to "control himself" after picking up an early booking against Celta Vigo just a week after seeing red in the Manchester derby.
And the Belgian, who is suspended for the next two Premier League games against Arsenal and Tottenham, is also expecting a difficult game against Celta in Manchester.
"We had control and we knew what we had to do," he told MUTV. "We created chances in the first half and we deserved the goal.
"It will be tough [in the second leg]. They are a good team. We have to give everything on Thursday, give everything to get to the final.
"We have a lot of injuries. It's difficult because we have a lot of games and we give everything in every game. We have to keep going and win at Arsenal [on Sunday].
"We have the players and the team and we want to do that."
United midfielder Ander Herrera hailed the defence for keeping a clean sheet on the night.
"We played well and controlled the game against a team that knows how to attack,'' United midfielder Ander Herrera said. "It's not easy to keep a clean sheet against Celta.''