Juande Ramos felt the first goal - not least the manner of it - changed the direction of our UEFA Cup group opener at Udinese as we lost 2-0 in Italy on Thursday night.
We'd looked comfortable against the Serie A high-fliers until the incident in the 23rd minute.
Benoit Assou-Ekotto aimed a backpass to Heurelho Gomes, who took a bad touch and then appeared to stumble as Udinese forward Quagliarella closed him down. The keeper then opted to try to go around the onrushing forward and eventually brought him down.
Di Natale made no mistake from the spot as we conceded our second early penalty in as many matches.
With the match still in the balance, Jamie O'Hara was sent off for two yellow cards 10 minutes into the second half.
Udinese had the upper hand from there but we still carved out an opening to equalise when Giovani's cross found Darren Bent six yards from goal in the 85th minute only for Udinese keeper Handanovic to tip over.
Seconds later and Pepe wrapped it up for the home side on a breakway goal.
"In the first half we played okay but the goalkeeper's mistake changed the game totally and in the wrong direction for us," reflected Juande at the Stadiu Friuli.
"If there was no mistake and we'd scored first then I think it would have been different.
"This kind of mistake can happen, it's part of football and I still support my players. Its part of the game.
"Udinese are a good team but it was easy for them after the mistake. If it happened the other way around it would have been completely different.
"In the first half we had good play and good chances but it's difficult to win if you don't score goals. We had opportunities to score the first goal but after the penalty it was difficult.
"I'm very angry because I don't like to lose. We've lost the first match of this small league and we now need to win matches to try and qualify for the next stage of the competition."