Mauricio Pochettino said it is difficult to accept Paris Saint-Germain's UEFA Champions League loss to Manchester City as he rued a game of "two different halves".
City seized control of the semi-final tie thanks to Thursday's (AEST) 2-1 victory in Paris, where Pep Guardiola's visitors produced a sensational second-half turnaround against PSG.
PSG captain Marquinhos opened the scoring in the 15th minute as last season's runners-up outplayed City in the opening half in the French capital.
But Kevin De Bruyne's cross found the back of the net just past the hour-mark and Riyad Mahrez's free-kick put City ahead seven minutes later, while PSG ended the match with 10 men following Idrissa Gueye's 77th-minute red card.
The Ligue 1 giants face an uphill task reaching the Champions League final for a second consecutive season as head coach Pochettino lamented the manner in which the Ligue 1 champions conceded.
"There were two different halves. In the first half we did well. We created chances and deserved the lead, but in the second half they were better than us," Pochettino told BT Sport.
"The two goals were accidents, but they created more than us. In the end it was one half for each of us.
"We're very disappointed with the two goals. It's difficult to accept that this happened in the semi-final – it's really painful. In the second half they were more consistent.
"It was difficult for us to cope. Physically they were a little bit more aggressive. It was difficult for us to recover the ball."
It was the first time PSG suffered Champions League defeat when leading at half-time since 2001 – against Deportivo La Coruna.
PSG are winless in their four European games against City (D2 L2), only facing Juventus (eight) on more occasions without ever winning in their history.
"In football you need to believe. We go there in six days and will try to win and score goals," said Pochettino, who guided Tottenham to the 2019 Champions League final after dramatically upstaging Guardiola's City in the quarter-finals.
"Of course we are under a little bit of pressure, but in football you need to try."