For a few days at least, the Blue Sharks can scent Argentinian blood. What a scene they presented at the end after drawing for a third time and improbably, magnificently, qualifying from Group H as runners-up. Their players and head coach, Bubista, huddled round a mobile phone to watch the closing stages of Uruguay’s defeat to Spain. They erupted en masse upon learning the outcome and can look ahead to a last-32 meeting with Lionel Messi and company in Miami. Messi’s meeting with this World Cup’s new cult hero, the goalkeeper Vozinha, could be one for the ages.

It would have been a travesty if Saudi Arabia, who made minimal impact despite requiring a win to progress, had snuck home here. What an insipid display this was from Giorgios Donis’s side, the gargantuan investment in their local league clearly yet to reap benefits at international level. The only surprise was that they were not picked off by one of Cape Verde’s numerous second-half counters. Anyone watching this tournament is pumped with advertisements for Fifa’s worldwide partner Aramco, the majority Saudi state-owned oil company, but their national team appear to need powering by alternative energy.

There was little doubting the neutrals’ favourites in Houston and there was absolutely no debate about the star attraction. Vozinha’s name was greeted with an ear-splitting roar when the teams were read out and the same occurred when, during the opening minutes, his face appeared on the stadium’s four giant screens.

Cape Verde had already been this tournament’s feelgood story but this time they needed to show the hardened edge of a team that could get over the line. It was tempting to think the hard work had been done in snatching draws from Spain and Uruguay but they were underdogs again on paper and any dropping of standards would be costly.

Nevertheless they could be excused wondering, in this most novel of situations, whether to stick or twist. The Saudis were the only team in desperate need of three points but in a featureless early spell nobody could have known. Donis’s players landed some hefty challenges, including a bizarre high tackle by Saud Abdulhamid, but could not deliver anything resembling a punch inside Cape Verde’s box.

It took 18 minutes for a morsel of goalmouth action to materialise, the Cape Verde right-back Wagner Pina hurling himself in front of a drive by Sultan Mandash that was angling across Vozinha. In return Willy Semedo, drafted in to start on the left, worked a good position before seeing Mohammed al-Owais save untidily.

At least it was something, and Cape Verde continued to look brighter after the now customary mid-half stoppage. One unwelcome pause was followed by another when Hassan al-Tambakti went down with a nasty-looking injury after a right-sided centre by Dailo Livramento had zipped across goal. The Saudi centre-back was carried off, replaced by Ali Lajami, and his teammates continued to come under pressure of sorts.

Lajami had to cut out a Pina cross and then Semedo, the ball dropping to him 20 yards out, cracked wide. These were tiny morsels but that was of little concern to Cape Verde, whose cause was furthered when Spain took the lead. The offering from Saudi Arabia was mindbogglingly meagre until stoppage time, when Mohamed Kanno rose to meet a perceptive ball Abdulelah al-Amri. It was the first half’s best chance by some distance but Kanno allowed Vozinha to make one of his easier saves of the past fortnight, not that the crowd were any less enthused.

Surely such a tedious status quo, of action rather than potential outcome, could not hold. Saudi Arabia had started the summer with a respectable draw of their own against the Uruguayans but, with everything on the line, were turning in a room temperature display. Three minutes after the restart Cape Verde could have applied punishment when Jamairo Monteiro did not connect cleanly from 15 yards and allowed al-Owais to gather.

Soon afterwards Kevin Pina, free-kick scorer against Uruguay, took aim from similarly preposterous range and was only narrowly off target with al-Owais grasping. Ryan Mendes was then crowded out after a promising run and, as the hour approach, Saudi Arabia were struggling to put together anything resembling a coherent attack.

Cape Verde simply looked hungrier than their opponents, Kevin Pina snapping incessantly at the base of midfield. Vozinha, perhaps keen for some work, extricated himself from a couple of potentially tricky moments on the ball. But the sense of a knife-edge was only going to grow with each passing minute. Saudi Arabia were hardly out of the picture.

They should have been in the 74th minute when Nuno da Costa, the substitute striker, held the ball up before slipping Laros Duarte clear. It looked like the moment for Cape Verde but al-Owais held firm and saved brilliantly, diverting the shot wide before receiving thanks from his teammates.

Not that they were providing much in return. Their only chance to break hearts came when Abdullah al-Hamdaan, allowed to test Vozinha from 15 yards, could only shoot straight at him. Cape Verde, who wasted further opportunities to settle the issue, had done enough.