KRASNODAR • Spain will head into the Russia World Cup starting on Thursday still unbeaten in 20 games under coach Julen Lopetegui, despite an underwhelming 1-0 win over Tunisia in their final warm-up match on Saturday.

But Lopetegui's search for a consistent centre-forward was made no clearer despite a solid showing from Brazil-born Diego Costa.

The Atletico Madrid forward set up Iago Aspas' winner six minutes from the end and was a nuisance throughout for the North Africans' defenders. On the back of a prolific 22-goal season in LaLiga, Celta Vigo striker Aspas continued his good form by rifling home a precise low strike from Costa's pass.

Costa and Aspas had started the 1-1 draw against Switzerland on June 3 and came on as substitutes on Saturday as Rodrigo led the line without reward against Tunisia.

Lopetegui, however, was keen not to give anything away on his attacking plans ahead of their opening Group B tie against European champions Portugal on Friday (Saturday morning, Singapore time).

Iran and Morocco are the other teams in the group.

"Nobody starts on a disadvantage versus the others," he said, when asked if Aspas has successfully staked a claim for a starting place in the first XI for the Portugal game.

"At the end, it's a decision you make thinking about the best solutions for the team.

"It's true you have to see the fitness of the player and whether he comes in at the right moment. Anyway, I wouldn't focus the discussion on the forwards.

"We gave similar minutes to the three strikers. In our last match, Iago and Diego started and Rodrigo entered later, while here it was the other way around.

"We wanted to give everyone a few minutes so that they'd arrive as well as possible. Pairing two of them was a solution in the final stretch of the match, when we switched to a back three, and it's an option for tacking the difficulties we're going to face.

"The most important thing is that there were no injuries. Now we have to fine-tune for our first game against Portugal."

Lopetegui shrugged off criticism that La Roja were lacking in penetration, saying that "it was a World Cup match" as Tunisia gave the 2010 world champions a tough workout.

"It's true the game was very difficult," he said. "We didn't achieve the rhythm we wanted in the first half and kept losing the ball.

"It was a World Cup match, but we grew against a team with plenty of rhythm, who drew with Portugal and went nine games without losing. The best thing is that the pace of the game was so high that it forced us to give Tunisia a game.

Meanwhile, Portugal held their first World Cup training session yesterday at the team's base in Kratovo, south-east of Moscow, five days ahead of their heavyweight opening clash against Spain.

All 23 players in Fernando Santos' squad took part in a 90-minute open training session held in light drizzle and chilly temperatures hovering just above 10 deg C.

Cristiano Ronaldo's presence elicited cheers from the 100 or so fans in attendance, with a similar number of media present.

Ronaldo said last week: "We know we are not the favourites, we have to be realistic. I think we must think match by match. The first match, the group stage will be extremely difficult but, I think that with these players, we need to think big and I am confident that we will give our best.

"What I can say is that we will always fight to the end, keeping hope that in football, everything is possible."

REUTERS, AGENCE FRANCE-PRESSE