Ronaldo curled in a stunning 88th-minute free-kick after being fouled by Pique in a thrilling 3-3 draw between the nations at the World Cup on Friday.
But Pique was unhappy with the fouls, saying Ronaldo regularly exaggerated contact.
"We have had more chances. They had three shots and scored three goals," the Barcelona defender said.
"Games go one way and you have to face it.
"Finding yourself in the opening game of a World Cup with a penalty against you in the second minute, you have to leave with good feelings after how the match went.
"Cristiano is prone to diving."
Spain dominated the majority of the contest, taking a 3-2 lead thanks to a Diego Costa brace and Nacho Fernandez's fine strike, before Ronaldo's late heroics.
But Fernando Hierro's men were left to rue a mistake by goalkeeper David de Gea, who fumbled in a straightforward Ronaldo strike late in the first half.
However, Pique defended his team-mate, saying: "He has been doing this for many years and we all face it, I'm sure that in important moments he will be how he has always been.
"A lack of confidence? Not at all, it's what you want to suggest. In the dressing room it's clear that David is our goalkeeper, he's shown it for years."