John Arne-Riise has apologised to Roma's fans after his error gifted Shakhtar Donetsk the winning goal in their Champions League tie.
Roma lost 3-2 at home after taking an early lead through Simone Perotta. But goals from Jadson and Douglas Costa gave the Ukranian side the advantage.
Then Riise surrendered possession on the touchline as he fell over gifting the ball to Costa, who squared for Luiz Adriano to make it 3-1.
And though Jeremy Menez pulled a goal back with a superb curling effort in the second half, Roma now face a tricky second leg in Ukraine.
"I know the fans are against me and I feel terrible about this," Riise told reporters. "That is football, but this was truly a negative match for me. We played fairly well and I made an incredible mistake on the third goal, but I think we can win in Ukraine.
"I was going to hit the ball long, but then I thought about it a moment more and lost my balance. I really don't know how I did it. I've had a similar experience with an own goal in the semi-final for Liverpool. I feel just sick, even physically.
"I hope the supporters can understand that I always give my all. I apologise to them. I went off at half-time because I made a mistake."
But despite shipping three goals in 13 minutes, Riise insists Roma can turn the tie around in Donetsk. He added: "We are physically in good shape, but concede too many goals. We're not playing the way we did last season. Nonetheless, I think we can win in Ukraine."
Roma boss Claudio Ranieri refused to criticise his men: "The team did everything it was meant to do. We knew Shakhtar's counter-attacks would cause us problems. We conceded a goal thanks to a double deflection, so those small incidents do change the game.
"We must accept this bitter defeat, but we did everything we possibly could, so I am satisfied with the squad. We were unable to equalise, but we will not give in.
"Douglas Costa is a phenomenon with a great left foot and is so quick in getting his finish away. Shakhtar have a very important future ahead of them and they kept hitting us between the lines, while they pass it around like Barcelona.
"We should've been more solid, but split apart for the first goal. Roma played a marvellous second half, but it all went against us."
Meanwhile, Shakhtar Donetsk coach Mircea Lucescu was not getting carried away by his team's triumph.
"Many people don't believe it, but we are a good team," Lucescu said. "We have played a great game and used our speed and our qualities to make life difficult for Roma. We have very good individual players and we took advantage of Roma's mistakes.
"But I believe the qualification is still open. We have to play in three weeks' time and I think Roma can win anywhere. I truly believe that Roma will come to Donetsk and play a different game."
"Roma were a different team in the second half," Lucescu said. "I thought they were excellent so I don't understand why their fans booed them."
Roma have a major hurdle to clear in the return leg on March 8 as Shakhtar have won all of their games at the Donbass Arena this season.