Czech Republic and Portugal remain level at 0-0 after 45 minutes of football in their Euro 2012 quarter-final encounter.
It was the Czechs who enjoyed an early spell of possession with Jaroslav Plasil and Petr Jiracek particularly lively.
Portugal improved as the 10-minute mark approached, however, with the pace of Nani and Cristiano Ronaldo causing the Czechs obvious discomfort.
Portugal's first real strike at goal came after 12 minutes when Joao Moutinho struck from distance. However, Petr Cech collected the danger.
It was the Czechs who continued to force the issue with a series of corners and Milan Baros might have turned home with an effort after 18 minutes.
Portugal's clearest opening came after 25 minutes when Nani fed Ronaldo, but Cech made a magnificent save. However, the skipper was ruled offside.
Ronaldo had another sighter after 33 minutes when he attempted an over-head kick inside the box, but it moved just wide of the target.
Ronaldo again came close moments later, but his long-range effort was always drifting away from the target.
Chances remained few and far between as the half developed, but Portugal had a penalty shout turned down on the stroke of the interval when Michal Kadlec felled Nani in the area.
Meanwhile, they came closer in first-half stoppage time when Ronaldo rattled the post from close range.