London - Mauricio Pochettino admitted Tottenham had only themselves to blame for Lionel Messi's mesmerising masterclass in Barcelona's 4-2 Champions League win at Wembley.
Pochettino's side found it impossible to subdue Messi as Barcelona ended their three-match winless streak in emphatic style.
The Spanish champions punished a howler from Tottenham goalkeeper Hugo Lloris to take a second minute lead through Philippe Coutinho.
Ivan Rakitic volleyed a stunning second goal for Barcelona before Harry Kane reduced the deficit after the break.
That set the stage for Messi to seize the spotlight once again as he netted twice either side of Erik Lamela's deflected effort for Tottenham.
Messi's brace was just reward for an irresistible display from the Argentina legend.
Messi already has five goals in the Champions League this season after hitting a hat-trick against PSV Eindhoven in Barcelona's group opener.
But Tottenham boss Pochettino claimed his side had made it easy on Messi with the error-prone start that forced them to throw players forward, leaving spaces at the back that the deadly Messi was able to exploit.
"Messi doesn't surprise me. We conceded the first goal and it is very difficult because that sets the game. We paid for that," Pochettino said.
"We had to give spaces when we were looking for a result. What happens is players like him can finish you off.
"After 45 minutes we didn't concede one chance to Messi. Of course in the second half when it's 2-0 and you give more space, it's so difficult to stop this type of player.
"He is the best in the world. With a lot of space it is unbelievable how he runs and dribbles.
"In the second half he was decisive. He's got that capacity and hunger for scoring."
Pochettino was frustrated that Tottenham gifted the initiative to Barca so easily, but he took heart from the way they pushed their star-studded opponents harder in the second half.
"Against a team that needed to win, to concede after two minutes, it destroyed the plan," Pochettino said.
"After making those mistakes, the first half was difficult for the team to be confident and play the way we planned.
"It's hard to assess the game. When you play a team like Barcelona you cannot afford to concede these type of chances.
"But for me, most important was the second half. We did everything to come back. We showed character and I'm so proud of the players."
Tottenham's hopes of qualifying for the last 16 from Group B are now in grave danger after two successive defeats.
Having lost to Inter Milan and Barcelona, Pochettino knows Tottenham must win their next European fixture at PSV Eindhoven later in October.
"We still need to play four games. We are going to have it in our hands to be in the next stage," he said.
"Of course it will be tough because now there are must-win games."
After three La Liga games without a win, including a shock loss to lowly Leganes, this was a morale-boosting success for Barcelona.
Another setback would have added to the sudden sense of crisis around the club.
And relieved Barcelona boss Ernesto Valverde admitted he was pleased with his side's stylish response to their recent woes.
"It's true that after a few bad results it was very important to do well today and we responded very well," he said.
"We want to always dominate and we did. Our response was very strong and effective.
"It was a great game against a difficult team."
Valverde was especially impressed with the way Barca stood up to late Tottenham pressure.
"The game was very intense. When it was 3-2, Tottenham made it very difficult for us," he added.
"We had a few problems in the game but we solved them and we just want to continue like this.
"I'm very happy with the players. Today's game was key for us."