Sheffield United manager Danny Wilson admitted Portsmouth gave his side a stern test as they claimed a 1-0 win at Bramall Lane.
Nick Blackman struck from the spot in the 66th minute after Lubomir Michalik's reckless sliding tackle felled Chris Porter inside the area to give the hosts a victory which takes them level on points with npower League One leaders Tranmere Rovers.
Wilson said: "It was a very tough contest. They've got some very experienced players who made it difficult for us at times. They played some great football, I have to say."
The Blades boss added: "There were pockets of the game where we played some great football as well. I think you could see there were two promising teams who will be challenging at the end of the season.
"We've dug out a great result again. For the penalty, maybe the boy committed himself when he shouldn't have done. It was a great penalty again from Nick.
"It was end-to-end and I think you've got to applaud both teams for going out and trying win the game. The onus is on ourselves and we defended very stoutly again.
"(Portsmouth manager) Michael (Appleton) has put a lot of players together in a short time but they've done very well and things can only get better from their perspective."
Appleton praised his side's performance and felt they were unlucky to lose, saying: "I thought we were very, very good for large periods of the game.
"I thought there were some really good performances and we had them on the back foot. We caused them a lot of problems and it was harsh to lose the game.
"A crazy little bit of defending from Lubo cost us at least a point. Even if he doesn't touch him, he was daft enough to go to ground when he didn't need to. He (Porter) was going away from the goal and it was just a rush of blood to the head."