Diego Costa's fluke goal edges Spain past Iran, closer to knockout rounds

KAZAN, Russia -- Three quick thoughts from Spain's 1-0 World Cup group-stage win over Iran at the Kazan Arena on Wednesday:

1. Costa's fluke edges Spain closer to last 16

It has been a World Cup of strange bobbles, ricochets and bounces, and this time it was Spain's turn to profit. Diego Costa knew little about the early second-half goal that broke Iran's resistance, which had threatened to turn a frustrating night into a hugely damaging one. But they all count and, while Iran could point to another hard-luck story after Saeid Ezatolahi's effort was ruled out for offside, the 2010 winners did enough to move to the brink of the knockout stage.

As expected, Spain's control of possession was near total. The problem was that Iran are a notoriously tough nut to crack and it was, in fact, Carlos Queiroz's side whose rapid counters produced the biggest early threat. One break brought a good run from the left-sided Vahid Amiri and another might have yielded more had Mehdi Taremi, on the opposite flank, not hesitated when sent behind the defence.

Those spurts became rarer and Spain began to create half-chances. From the best, David Silva hooked a tumbling volley over on the half-hour mark. Silva saw another shot blocked and one more deflected wide; he seemed to have got the memo that, against opponents so determined not to be pulled apart, there was merit in having a crack from range.

By the time the interval arrived, though, the only major ignition point had been a scuffle when Iran goalkeeper Ali Beiranvand went down dramatically after a tap from Costa.

Beiranvand was more constructively involved in the opening moments of the second half, pawing away a 20-yard shot from Sergio Busquets. Spain had emerged looking a much bigger threat, Gerard Pique also seeing a header scrambled away, although Iran themselves came within inches of scoring when Karim Ansarifard brushed the side netting.

Suddenly a goal, at one end or the other, seemed likely. It came in fortunate fashion for Costa, who looked to turn onto an Andres Iniesta pass and saw Ramin Rezaeian's clearance cannon in off his shin.

Now Iran had to commit men forward and they wheeled away in delirium when Ezatolahi drilled past David De Gea from close range. Their joy was cut short -- eventually -- by an offside flag; a VAR check confirmed the decision and Spain survived. Eight minutes from time Taremi thudded a free header over at the far post and Iran's luck was conclusively out.

2. Vazquez flop leaves selection debate rumbling on

This was hardly vintage fare from Spain and, in the buildup to their deciding group game against Morocco, the debate over Fernando Hierro's best starting lineup will rumble on. Here he opted for energy and speed in the form of Lucas Vazquez, who started on the right flank. With Dani Carvajal back from injury and supporting from full-back, the plan seemed to be that Spain would operate at a high tempo against opponents who would pack their defensive ranks and, perhaps, eventually tire.

Vazquez's selection in place of Koke was a particular source of controversy. Nobody doubts the 26-year-old's directness and willingness to put the yards in; the issue is that he lags behind the likes of Koke and Marco Asensio in creative terms and, while his delivery from crosses can be incisive, more nuance might be needed to break the lines.

That proved to be the case, Vazquez enduring a virtually anonymous first half as Iran -- operating with virtually a six-man back line -- squeezed the life out of the game. Spain's driving force was Isco, on the opposite wing, who produced some delightful touches and probed menacingly. Silva was tireless too, making a vital contribution to Costa's goal, but the team's balance does not seem quite right and the question over that final attacking midfield spot remains.

As well as Koke and Asensio, Thiago Alcantara and perhaps Saul Niguez can lay their own claims and the time will come when Spain need to know they are getting a reliable end product. Vazquez's selection made sense in terms of shape and dynamism; in practice he offered little and, with an already eliminated Morocco likely to give up chances on Monday, the time may have come for Hierro to try Plan C.

3. Iran's World Cup far from over

An evening that looked relatively risk-free for Iran ended in frustration and more than a pang of regret, but "Team Melli" showed more than enough to suggest they can still make the round of 16.

There was a sense from the outset that Queiroz regarded this as something of a free hit: He left captain Masoud Shojaei and star wide man Alireza Jahanbakhsh out of his starting XI and it seemed no coincidence that both picked up yellow cards in the win over Morocco. Monday's meeting with Portugal in Saransk will be decisive to their fortunes and the risk of losing either player appeared too great.

Iran's plan was, on the face of things, quite simple: They would let Spain have the ball, defend with 11 behind it and, on the rare occasions when they could retain it for any period of time, look to break sharply. By the midway point in the first half, their setup essentially resembled a flat back six when defending their own box. If they lived dangerously once or twice, then on the whole they looked comfortable and it is worth remembering that this, after all, is what Iran do best.

They are a coiled spring, adept at soaking up pressure and -- led by Sardar Azmoun, who plays his club football in this stadium for Rubin Kazan -- posing a genuine threat when committing men forward. It is a formula that almost thwarted Spain and should be good enough to trouble Portugal in a match that is now win or bust.

They will, at least, be able to count once more on a marvellous travelling support that made a deafening noise inside the Kazan Arena and almost caused an earth tremor when they thought Ezatolahi had brought them level. It was not to be but, for Iran, this World Cup is nowhere near over yet.