ANOTHER victory for Spain, one that all but assures them of their place in the quarter-finals, but it will take more than that to convince anyone, not least their own fans, that they are ready to mount a serious challenge for their first major trophy in 44 years. History, perhaps, should not be used to pre-judge this side, but so often have Spain burned too bright, too soon, that it is difficult not to see this tournament following the familiar narrative arc from high expectations and early achievement to agonising underachievement.

The question mark, as ever, is not so much over talent, which they have in abundance, as over temperament. After Tuesday's 4-1 win over Russia, there seemed to be a conscious effort on the part of Spain not to get too carried away, but the sense of anti-climax yesterday was nonetheless palpable. They could console themselves with the thought that they almost totally dominated the second half, but still, the difference in the two performances was like the weather. On Tuesday it was all Sturm und Drang and lightning flashes over the Alps; yesterday it was mainly damp and grey. "It's difficult to play against a team that uses five defenders all the time," said the Spain manager Luis Aragones, "and it's difficult to play against opponents who are all 20cm taller than you."

That's as may be, but what will worry Spain is what happened in the game's second quarter, when Sweden had them largely penned back in their own half. It's all very well having arguably the most potent strike partnership in the tournament, but it matters little if you can't get the ball to them. That David Villa finally found a winner, three minutes into injury-time, was more down to Sweden's exhaustion after a prolonged pummelling than to any measure of creativity.

There must also be a huge question-mark over Spain's back four. Even with Villarreal's Marcos Senna – one of the many Brazilians who have somehow been smuggled into the tournament – sitting deep in the midfield they look distinctly creaky yesterday, a situation that only got worse when Carles Puyol went off after 24 minutes to protect a thigh strain and was replaced by Raul Albiol.

The brilliance of their forward play rather disguised their ricketiness in the 4-1 win over Russia, but last night the mind went back to the chance that Konstantin Zyryanov had to make it 1-1 that came back off the post. It seemed at the time an aberration; in retrospect it was a warning, and one that Spain failed to heed. Sweden's equaliser arrived after 34 minutes, but there had been plenty of signs it was on its way.

Henrik Larsson, age slowing his body but not his mind, had cleverly set through Johan Elmander to drive a shot into the side-netting, and then, laid on himself by Zlatan Ibrahimovic, had scooped a tumbling shot just over. Spain's response was merely to fall deeper, meaning that when Anders Svensson's ball in from the right found Ibrahimovic at the back post he had time to control it and slip Sergio Ramos on the turn before squeezing a shot under the dive of Iker Casillas.

Ibrahimovic had not scored for his national team in almost two years before Tuesday's exquisite strike against Greece. He is an anarchic, temperamental presence, given both to the sort of mischievous ingenuity that had him startling punters by impersonating a policeman in Malmo's red light district and to sulky ineffectualness. Having got him in the right mood at last, it must be deeply galling for Sweden to see him succumb to a swollen knee at half-time yesterday. Marcus Rosenberg, the Werder Bremen forward who replaced him, may be quick, but he does not set the pulse racing as Ibrahimovic does. Indeed, yesterday, he barely got a kick.

There can be little doubt that the loss of Ibrahimovic affected Sweden profoundly. Without him they were forced onto the back foot, and the change of emphasis proved their undoing. "I don't know if we're too dependent on him," said the Sweden manager Lars Lagerback, "but you have to remember he's a world-class player. He did a great job in the first half tying opponents to him and holding the ball up."

Sweden had been punished for their one mistake of the first half, as Fernando Torres drifted in front of Hansson to deflect David Silva's cross past Andreas Isaksson, and it was presumably a measure of punch-drunkenness that led to the second as Torres flicked on a long clearance to Villa, who cut inside Hansson before calmly beating Isaksson.

"It was the most important goal of my career," said Villa, who moved onto four goals for the tournament, one clear of Lukas Podolski in the race to be top scorer. "It was a collective triumph. I'm not bothered about the golden boot; it's all about the team and our progress."

Tactically, Spain were unexceptional, they were largely unimaginative, and they were defensively suspect but, at least against a team of Sweden's level, all those things can be overcome with two strikers of the quality of Torres and Villa. The idea of strike-partnerships may be going out of fashion but theirs is one that works. Whether it is enough to go all the way is questionable.

Sweden: Isaksson, Stoor, Mellberg, Hansson, Nilsson, Elmander (Sebastian Larsson 79), Andersson, Svensson, Ljungberg, Henrik Larsson (Kallstrom 87), Ibrahimovic (Rosenberg 46).

Spain: Casillas, Sergio Ramos, Marchena, Puyol (Albiol 24), Capdevila, Iniesta (Santi Cazorla 59), Senna, Xavi (Fabregas 58), Silva, Villa, Torres.

Referee: Pieter Vink (Holland).