Barcelona playmaker Deco put Portugal in front early in the game but Libor Sionko drew the Czechs level in the 17th minute.

Ronaldo restored Portugal's advantage three minutes past the hour mark before assisting substitute Ricardo Quaresma for the third goal in stoppage time.

Portugal's second successive victory put them on top of Group A on six points, three ahead of the Czech team.

Switzerland and Turkey, who both lost their EURO opener, meet later on Wednesday.

Deco needed eight minutes to break the deadlock despite Petr Cech's determined attempts to clear the danger.

Ronaldo played a neat one-two with Nuno Gomes inside the area but Cech intercepted to deny the Manchester United winger.

Deco reacted to slot home on the rebound after Cech tried in vain to push the ball away.

Sionko leveled the score in the 17th minute when he met a right-wing corner with a superb diving header that went past Portugal keeper Ricardo.

Czech Republic had to thank in-form goalie Cech for denying Portugal on numerous occasions.

He blocked a fierce drive from Ronaldo three minutes before the break.

The Chelsea guardian was called into action again in the 58th minute when he smothered Simao's low shot.

Ronaldo wasn't at his best but managed to restore Portugal's lead six minutes later. He was as effective as ever.

The 23-year-old connected with Deco's cross from the right to send a precise low shot past Cech, who was blameless for the goal.

In stoppage time, Ronaldo beat the offside trap when he ran onto a deft through pass before squaring to Quaresma for an easy tap in.