Celtic were sent crashing out of the Uefa Cup by Villarreal after their defence and attack deserted them here last night.
Sonny Anderson and Roger Garcia seized on some shoddy defending by Celtic to put the Spanish side on course for the Gothenburg final.
Celtic's chances were hit before kick-off when striker Chris Sutton failed to recover from a groin injury. The Hoops were already weakened by the suspension of Alan Thompson.
Martin O'Neill's men got off to the worst possible start, falling behind on aggregate after just six minutes, when Juliano Belletti hung the ball in the air from the right and Anderson reacted to hesitancy from Bobo Baldé to head the ball over goalkeeper David Marshall from just inside the box.
Celtic's defence were all over the place in the first 20 minutes and were grateful for the profligacy of Villarreal, who wasted some easy chances as first Jose Mari fired over the bar from 14 yards and then Anderson stood on the ball when clean through.
With Henrik Larsson alone in attack, Celtic struggled to trouble Villarreal's defence. Celtic had claims for a penalty turned down on the half-hour as Jackie McNamara seemed to get tripped in the box before they squandered a glorious chance soon after as Stephen Pearson headed over from eight yards.
Celtic managed to step up the tempo after the break but the Villarreal defence held strong. They did look vulnerable, though, in the 55th minute when Larsson got on the end of Didier Agathe's cross to head narrowly wide.
Liam Miller was then presented with a decent chance in the 62nd minute when Neil Lennon's free-kick hit Stanislav Varga and landed at his feet but he blazed his left-foot shot high and wide.
Marshall then came to Joos Valgaeren's rescue moments later when he was forced to scurry across his goal line to hold his backward header by his post.
But Celtic's mission became almost impossible in the 68th minute when the Spanish side increased their advantage. Anderson was the provider this time as he crossed from the left and Garcia beat Valgaeren to the ball and blasted the ball past Marshall.
Despite O'Neill shuffling his pack with two late substitutions, Celtic could not find a way through Villarreal's defence and Larsson's late free-kick, which was fired high over the crossbar, summed up Celtic's night.
O'Neill, who blamed the exit on individual mistakes and the absence of key players, said: "I thought that the first goal was avoidable. It put us on the back foot for 10 minutes.
"It was just a long ball and the defence may have thought the ball was going to carry to David Marshall. Bobo seemed to leave it and very quickly Anderson was on to it like a flash. It was a poor goal to concede.
"That certainly knocked us back but I thought we regained our composure. I was happy until the second goal but that just about killed us."
Villarreal (4-4-2): Reina; Arruabarrena, Coloccini, Belletti, Ballesteros; Josico, Roger, Battaglia, Riquelme; Jose Mari (Javi Venta, 86), Anderson. Substitutes not used: Lopez Vallejo (gk), Marti, Victor, Guayre, Quique Alvarez, Calleja.
Celtic (4-4-2): Marshall; McNamara, Valgaeren, Baldé, Varga; Agathe, Lennon, Miller (Smith, 72), Petrov; Larsson, Pearson (Wallace, 72). Substitutes not used: Douglas (gk), Sylla, Lambert, Mjallby, Beattie.
Referee: Massimo De Santis (Italy)