Cristiano Ronaldo was the centre of attention as Manchester United confirmed their place in the next stage of the Champions League.
For the second successive match, the Portugal winger had to endure some stiff challenges. He was left with cuts on his ankle at the weekend in the 0-0 draw against Aston Villa.
Then tonight he was the victim of a high challenge for Joan Capdevila that saw him dismissed with seven minutes to go.
Ronaldo had come closest to making the breakthrough in the first half but his effort was tipped onto the bar by Diego Lopez.
He certainly showed no ill-effects from the ankle problem he suffered at Villa and Villarreal had trouble containing him. But the fourth successive match these teams played out a goalless draw.
United looked the more assured of the two sides throughout the game but it took them until the 41st minute before they made a real impact.
There was a scare for Villarreal at the start when Anderson delivered a ball from the left but it was punched away by Lopez as Wayne Rooney waited to pounce on any mistake.
Ronaldo was angered in the seventh minute after tussling with Ariel Ibagaza and both players were spoken to by referee Roberto Rosetti. Ibagaza, however, had appeared to dig his nails into Ronaldo's neck.
Villarreal then carved out a good chance in the 17th minute and Tomasz Kuszczak had to show good reactions to beat away a shot from distance from Santi Cazorla.
Ronaldo was left on the floor 10 minutes later after a stiff challenge from Javi Venta which saw him booked.
The United winger sent a 25-yard free-kick into the arms of the goalkeeper.
Ronaldo then chested the ball back to Darren Fletcher in the 35th minute but again Lopez was able to make a comfortable save.
United almost took the lead in the 41st minute when Rooney laid the ball off to Ronaldo with an exquisite touch.
Ronaldo rattled in a goal-bound shot but Lopez got up well to turn his effort onto the bar.
Then a minute later Lopez again denied Ronaldo by turning his free-kick around the post in a good spell of pressure by United. Ronaldo started the second half as he ended the first by skipping forward in the 51st minute. He rattled in a shot from an acute angle that Lopez parried at the near post.
The winger was astonished to be booked a minute later for not retreating when a free-kick was awarded.
United kept up the pressure and Fletcher found himself clear on the edge of the area in the 57th minute, only to drag his effort wide of the post.
Fletcher then released Rooney and his chip beat Lopez but went narrowly wide of the post.
It was Anderson's turn next but the shot was soft and Lopez was able to gather safely.
Villarreal responded in 65th minute and Cazorla delivered a good cross from the right but the ball skidded away from Capdevila at the last minute.
It was brief respite for the home side with Rooney then testing Lopez with a good volley.
United almost took the lead in the 79th minute when Rooney's cross took a deflection but Capdevila cleared off the line.
Villarreal were then reduced to 10 men four minutes later when Capdevila was sent off for a high challenge on Ronaldo has he tried to race down field.
Despite being a man up, United had little time to make their advantage pay. However a draw confirmed both teams place in the next stage.Reuse content