Porto’s defense held firm to frustrate Panathinaikos and earn a 0-0 draw in their Champions League second-phase Group C match late on Wednesday. The hosts dominated throughout with the powerful Michalis Constantinou a constant threat. But the Portuguese, marshaled at the back by Jorge Andrade and Ricardo Cavalho, didnot put a foot wrong under relentless pressure. Constantinou fired a header wide after six minutes and strike partner Emmanuel Olisadebe should have done better from close range minutes later. Porto, who have never won a Champions League clash in Greece, nearly snatched the lead in the 17th minute as Deco forced a fine near-post save from Antonis Nikopolidis. Panathinaikos continued to hunt for the opener with Olisadebe coming close with a powerful header and a left-foot shot. The Nigerian-born Pole drove a right-foot effort onto the upright just short of the hour but it was as close as Panathinaikos would come to the breakthrough. Panathinaikos coach Yiannis Kyrastas was left to rue bad luck and missed chances after his side had dominated without scoring. This game leaves a bitter taste, said the Greek coach. We were denied by two factors. The first was the tension showed by specific players in the opposing penalty area. The second was that luck was just not on our side tonight, he added. Porto coach Octavio Machado, happy with his side’s master class in defending, was less inclined to view the result as lucky. Luck is just part of the game whether it is good for you or bad for you, he said. Kyrastas said Panathinaikos had been surprised by the visitors’ negative approach. We had been expecting a more attacking Porto. As it is, they came looking for the result and they got it, he said. The Porto coach was reluctant to reveal the secrets of their flawless rearguard action, while revealing that the Greek attack had played as expected. Panathinaikos have great strength in the center of their attack and that’s where the danger was as they were coming forward with the ball all the time, he said. Kyrastas couldn’t fault his players for effort but attacked their lack of calm in the penalty box. We had the attacking approach right from the kick-off. We created so many chances but the nerves in the area stopped us claiming a deserved win, he said.