Gordon Strachan last night spoke of his disappointment as Celtic lost to a soft free-kick to Villarreal and described the task of qualifying from Group E as �right hard work�.

Gordon Strachan last night spoke of his disappointment as Celtic lost to a soft free-kick to Villarreal and described the task of qualifying from Group E as "right hard work".

"It is a mountain to climb," he said, forgiveably slipping into cliche after enduring a draining night in El Madrigal that leaves Celtic with one point with Old Trafford and Manchester United beckoning.

Marcos Senna scored the goal that condemned Celtic to another away defeat in the Champions League when he converted a free-kick after 66 minutes after Joseba Llorente went down easily under a challenge from Paul Hartley.

"I had a look at it and I'm not convinced it is a free-kick," said Strachan. "The players are not convinced it was a free-kick that's for sure. Only the player will know if he dived. I can't point the finger at anybody. That would not be right. Only the pictures will tell you."

However, the Celtic manager was encouraged by what he described as the best Celtic performance in the Champions League under his command. "We wanted a performance," he said.

"The first-half performance and the first 10 minutes in the second half were excellent. We played against a right good side and gave them a right good game. We were always a threat, particularly on the counter attack. We were reasonably comfortable at the back."

However, he said Villarreal then pushed his side back after an hour. "We were dragged back. Then we could not keep the ball long enough. That is something to work on something to get better at," he lamented.

He was effusive, however, about the quality of the side who are at the top of La Liga. "They showed what a right good side they are. In Senna they have a world-class player," he said.

However, Celtic played with some verve and enterprise. "They must be really pleased," said Strachan of his players. "That is the first time I have sat there and said: I like what I am seeing away from home'." He conceded, however, his side needed that touch of ability just "to finish chances off".

Both Scott McDonald and Georgios Samaras had good opportunities but the Australian's shot flew over and the Greek's effort in the first half was saved by Diego Lopez.

"Scott was a problem to them when he came on," he said. He stressed, however, on a night that extended a Champions League winless away run to 16 games: "We showed we belong at this level. That performance was good enough to win at most places. It was just unfortunate that we came up against one of the best teams in Europe at the moment."

He would not admit that Celtic were not battling for the UEFA Cup spot with Aalborg, who lost 3-0 to Manchester United and are at the bottom of Group E with Celtic with just one point. "We will see how it goes in the next couple of games and we will talk then," he said.

He added, however: "Tonight is the most comfortable we have looked as a force."

Celtic have now not scored in four successive away games in the group stages of the competition but Strachan said his team had looked likely to break that duck last night. "The team that was playing us had to watch us. That has not always happened," he said of Celtic's travels in Europe.

Manuel Pellegrini, the Villarreal coach, said he did not think the score reflected the true gulf between the sides. He said: "They didn't gives us a lot to do. They obviously came for a point."

However, the Chilean would not rule Celtic out of the race for qualification.

"The points are there to play for. It's all to play for," he said.