Cristiano Ronaldo's hunger is as great as his talent. His persistence in Portugal's cause was inexhaustible until he scored the only goal of this Euro 2012 quarter-final when there were only 11 minutes remaining. Czech Republic are not without skill but they were eventually pinned down by opponents who now face France or Spain in the last four.

The Portugal coach Paulo Bento could not have been pleased that technical superiority took so long to achieve the breakthrough with Ronaldo's header from a João Moutinho cross. However, he approved of the way in which his men refused to succumb to an exasperation that could have undermined them.

"We showed a great capacity to react to the Czechs," said Bento, who saluted Ronaldo. "In a dynamic game he played accordingly." The striker has three goals at the tournament. His freshness is almost as noteworthy as his talent. This has been a long season for him with Real Madrid and has included the hurt of defeat in the Champions League when he missed his penalty in the shootout that sent Bayern Munich to the final with Chelsea.

There is a persistence to Ronaldo that is not appreciated because the trappings of stardom catch the public's eye more readily than the way in which he applies himself.

Now that the tournament is moving into an advanced stage, the questioning of the surviving teams will get ever more stringent. The Czechs had at least put up a fight after being beaten 4-1 by Russia in their first match. They also had the most of whatever boldness there was in the first-half, with enough intent to ensure that Portugal's supply to Ronaldo was spasmodic. For their part, the Czechs would have been frustrated that Tomas Rosicky was stuck on the bench after being unable to recover fully from his achilles injury.

If press conferences are any guide, Bento will never be found guilty of getting anyone overexcited. You can still see in him the hard-working midfielder he once was. Bento's opposite number Michal Bilek may also have an understandable caution, considering that he might have been sacked in a trying start to the qualifers when Lithuania won in Olomouc.

In this match, he did not appear to have substantial means but Portugal were initially kept at bay. The Czechs had no intention of being passive, yet there was little that was clear cut in attack. Even Ronaldo had some frustrations and the difficulties intensified when his team-mate Hélder Postiga seemed to pull a hamstring, with Hugo Almeida taking over in the 40th minute.

It was a night when players were thwarted in the first-half. Ronaldo, all the same, was very close to being the exception on the verge of half-time. Taking a ball from Raul Meireles on his chest, he turned away from Michal Kadlec and hit the post with a volley. It looked then that Ronaldo was the one feasible source of a goal.

The nature of the match ought to have been anticipated. There was some sense of adventure but it had its limits, Considering the prize being fought over, the players were limited in the level of risk they would take. Each coach, if not happy, would have seen no sense in adopting radical measures when there was no crisis. As it was an opportunity would be wasted at the beginning of the second half.

Almeida was presented with the ideal cross from Meireles but headed it high. Ronaldo then brushed the post with a free-kick and there was convincing evidence that Portugal were gradually improving their accuracy. Nani came into the action to demand a save from Petr Cech.

The Czechs strove to alter circumstances and introduced Jan Rezek for another attacking midfielder, Vladimir Darida. While Portugal would have felt entitled to be leading, the old complaints about finesse being far more apparent than finishing had relevance. There had, too, to be an appreciation of the doggedness and organisation of the Czechs.

The balance of power had not shifted but Portugal had to deal with being thwarted again as a Nani shot was denied when it clipped a defender and went narrowly wide. Bento's side needed their reserves of patience and were duly rewarded by Ronaldo.