Holland winger Arjen Robben believes he is not yet at his best despite earning the man-of-the-match award against Slovakia.
Robben scored Holland's opener in their 2-1 triumph yesterday to seal a place in the quarter-finals of the World Cup against Brazil.
It was all the more rewarding considering the Bayern Munich winger earned his first start of the tournament against the Slovaks after only just recovering from a calf injury.
"It was a great feeling to start this game," Robben said. "I think it was also good to feel important for this team."
Robben broke the deadlock in the first half after beating two defenders before firing home.
He continued to terrorise the Slovakian defence with great pace and skill.
"I am not yet at my top level but I was pretty confident," he added. "It was a great pass by Wesley Sneijder and my shot was good enough.
"I waited for the right time as I had two defenders on me but I found the space."
Holland have won all of their four games in South Africa but Robben admitted yesterday's game was far from their best performance.
"It was a difficult match," he said. "We didn't play our best game but, at the end of the day, it's all about winning.
"I hope we will save our best match for our next game. We want to improve. We know what people have said in the past, that we play well but we don't get to the end.
"Against Slovakia we were efficient."
Robben is confident the Dutch can hit top form in Friday's quarter-final against Brazil in Port Elizabeth.
Brazil beat Chile 3-0 to progress to the last eight.
"We were not at our best against Slovakia but I think we will be on Friday," said Robben.
Slovakia coach Vladimir Weiss had predicted that Robben would prove the difference and he was right.
"We were preparing for Robben for the past few days," said Weiss. "But he is an absolute genius. He is a great player.
"When I saw him in the line-up for the game I knew he would make Holland's team 50% stronger and I was correct."