Ruiz’s impressive header was enough as the Ticos won 1-0 to become the first team to guarantee qualification from Group D.
“I cannot explain the emotions I am feeling right now,” said Ruiz last night.
“We had dreamed of this moment, even though we knew people didn’t believe in us. We qualified ahead of teams much stronger than we are, so this is all a dream come true.
“We thank all those who did believe in us, as we’ve achieved something extraordinary, considering our country is so small.”
Italy coach Cesare Prandelli admitted two missed chances by Mario Balotelli had proved costly.
“Mario played well in the first half and had two chances and if he had scored then, the game would have been different,” he said.
Asked if he had a message for England, who had been relying on an Italian victory, Prandelli added: “I am terribly sorry not just for the English but also for us, as we wanted to win.
“Now we will have to play well against Uruguay in order to qualify. We have to try to recover our energy for the Uruguay game in four days.”
Italy and Uruguay will battle it out for the other qualification spot — the Azzurri need only a draw — but England will only be playing for pride in Belo Horizonte on Tuesday.
Costa Rica showed their 3-1 win over Uruguay was no fluke as they took the game to Italy in impressive style.
Celso Borges headed over from a corner early on, but it was Italy’s Mario Balotelli who had the best of the chances in the first half-hour.
First, Andrea Pirlo’s glorious ball over the top dropped perfectly for Balotelli, who controlled it with one touch and then lofted it over the on-rushing keeper Keylor Navas but it bounced well-wide, and the former Manchester City striker held his head in his hands.
Two minutes later and Balotelli was in again, this time he went for power but too close to Navas, and the Costa Rica keeper was able to claim at the second attempt.
With half-time looming, Costa Rica were denied a blatant penalty.
Joel Campbell, the Arsenal striker currently on loan at Olympiakos, intercepted a pass, surged into the penalty box and was knocked over from behind by Giorgio Chiellini but Chilean referee Enrique Osses inexplicably waved play on.
Costa Rica did not let that put them off their stride, however, and Junior Diaz’s exceptional cross from the left saw Fulham striker Ruiz, leaving his marker Chiellini in no man’s land, thump a far-post header in off the crossbar. It bounced a foot over the line but goal-line technology ensured the goal was allowed to stand.
Italy upped their game after the break, realising defeat would leave them vulnerable against Uruguay, with Parma striker Antonio Cassano coming on for defensive midfielder Thiago Motta.
Balotelli claimed a penalty of his own under challenge from Oscar Duarte, but it was not nearly so clear-cut as Costa Rica’s, the referee once again turned away.
Italy mounted a series of attacks but Navas was having a blinder in the Costa Rica goal, first tipping over Matteo Darmian’s angled drive, and then turning aside Pirlo’s free-kick after Cassano had hurled himself to the floor to earn it.
Costa Rica still looked dangerous on the break and Gianluigi Buffon had to be quick out of his goal to clear the danger, with Campbell about to pounce.
Italy continued to hustle and bustle but the Ticos kept the danger away from their goal, while at the other end Chiellini’s block denied substitute Marcos Urena.
Randall Brenes was a yard away from scoring a sensational second in injury time but it mattered not — Costa Rica were through and England’s fate was sealed.
ITALY: Buffon, Darmian, Barzagli, Chiellini, Abate, Thiago Motta (Cassano 46), De Rossi, Candreva (Insigne 57), Pirlo, Marchisio (Cerci 70), Balotelli.
COSTA RICA: Navas, Gamboa, Umana, Duarte, Diaz, Gonzalez, Ruiz (Brenes 81), Borges, Tejeda (Cubero 67), Bolanos, Campbell (Urena 74).
Ref: Enrique Osses (Chile).