Inter Milan blew the chance to go top of Serie A when they were held to a 2-2 draw by Parma at San Siro on Saturday.
Antonio Conte's side fought back through a Romelu Lukaku strike after the break but it was not enough to take advantage of a Juventus slip-up.
The champions were held to a 1-1 draw at Lecce earlier in the day but they remain top of the table on 23 points, one point ahead of Inter in second.
"We played an ugly first half," Candreva told InterTV. "We were better after the break, but we regret not having won. We're regretful and angry about how it went."
Inter took the lead midway through the first half when a corner was headed into the path of Candreva, whose low strike took a deflection on its way past Luigi Sepe in the Parma goal.
The visitors reacted swiftly with two goals in four minutes as Karamoh, who left Inter for Parma in the close season, lashed the equaliser past home keeper Samir Handanovic before setting up Gervinho to finish off a clinical counter-attack.
Conte's side levelled early in the second half in strange circumstances as Lukaku's bundled finish from a Candreva cross was ruled out for offside until a lengthy Video Assistant Referee (VAR) review overturned the decision.
The goal saw the Belgian become the first Inter player since Diego Milito in 2009 to score as many as six goals in his first nine league games for the club.
Inter pushed for a winner late on as Stefan de Vrij headed over from a corner and fellow substitute Sebastiano Esposito's well-struck volley flew just wide.
"There are regrets that we didn't hold on to the lead but on the other hand considering how many players were out injured and the team we were up against, we can be satisfied to take a point home from this fixture," Parma coach Roberto D'Aversa told Sky Italia.
"The lads gave everything for 97 minutes and honoured the jersey."