And with Mbappé in that kind of form, it's hard to see Barcelona staging another epic comeback this time.
After Messi put Barcelona ahead from the penalty spot, Mbappé netted a hat trick at the Camp Nou Stadium on Tuesday to give PSG a 4-1 win in the first leg of their round-of-16 matchup.
It was the team's first meeting since Barcelona erased a 4-0 deficit by winning the second leg 6-1 at the same stage of the competition four years ago. But Ronald Koeman's team was thoroughly outplayed at home, even with PSG missing Brazil star Neymar, and now has to attempt a comeback in Paris instead.
"It was a very important match for us," Mbappé said. "We wanted to come here and win. We did that in style. Tonight was magnificent, but we haven't won anything yet."
Mbappé scored five minutes after Messi's opener and added two second-half goals to become the first player to score an away hat trick at the Camp Nou in the Champions League since Andriy Shevchenko for Dynamo Kyiv in a 4-0 win in 1997.
His dominance was epitomized by the image of Barcelona captain Gerard Pique — making his return from a long-term injury layoff — pulling at Mbappé's shirt in an unsuccessful attempt at slowing down the France star as he rushed forward in attack.
"There's no doubt that Kylian is one of the best players in the world, despite his young age," said PSG coach Mauricio Pochettino, who was in charge of his first Champions League game with the French club, having led Tottenham to the final two years ago. "He's already done extraordinary things. But we have to stay humble."
Moise Kean also scored in the second half for PSG, last season's finalist which looked far more dangerous than the hosts throughout the match at the empty Camp Nou.
The second leg will be on March 10 in Paris. Liverpool defeated Leipzig 2-0 in the other round-of-16 match on Tuesday.
"I'm not going to lie, it's very difficult to come back from a 4-1 first-leg loss at home," Koeman said. "They were better than us. They were very efficient, especially Mbappé. In the second half we had problems and PSG showed that they are physically much stronger than us."
The defeat deals another tough blow to Barcelona, which has been struggling financially and enduring political turmoil since the embarrassing 8-2 loss to Bayern Munich in last season's quarterfinals.
"We needed an almost perfect game against them and we couldn't do it," Barcelona forward Antoine Griezmann said. "It's tough when they score four goals on you at the Camp Nou, but we will go to Paris to try to advance, we won't go there just as tourists."
Barcelona was in control early on and opened the scoring with a 27th-minute penalty after Frenkie de Jong fell in the area when his heel was clipped by defender Layvin Kurzawa.
Messi fired a left-footed shot into the top corner for his 10th goal in the last 10 matches. It was Messi's record 28th goal in 31 matches in the round of 16 of the Champions League, according to UEFA. He has scored in the tournament for the 17th consecutive year — from 2005 to 2021 — to match Raúl González's feat from 1995 to 2011.
PSG immediately pressed forward and equalized five minutes later after a nice exchange of passes inside the area, with Mbappé controlling the ball and shooting it into the top of the net from close range after a clever one-touch pass by Marco Verratti.
PSG continued to play better and Barcelona goalkeeper Marc-André ter Stegen had to make a few good saves before Mbappé put his team ahead from inside the area in the 65th.
Kean added to the lead five minutes later with a header off a free kick, and Mbappé sealed the scoring by finishing off a quick counterattack by curling a first-time shot into the far corner in the 85th.
The goals allowed Mbappé to pass Pauleta for third place on the club's all-time scoring list with 111 goals.
PSG was also without Ángel Di Maria because of an injury. Neymar was a Barcelona player in the round-of-16 match in 2017, when he led the team's comeback with a great performance and two goals after the first-leg loss in Paris.
Barcelona also was depleted by injuries but saw the return of Piqué after he was sidelined for nearly three months because of a knee problem. Also out were Philippe Coutinho and Sergi Roberto, who scored the sixth goal five minutes into stoppage time to seal Barcelona's comeback in 2017.
Barcelona and PSG also met in the knockout round of the Champions League in 2013 and 2015, with the Spanish powerhouse coming out on top each time. PSG last advanced past Barcelona in the 1995 quarterfinals but now has the chance to repeat that feat in three weeks.
"There are 90 minutes left and they have great players," Pochettino said. "There's still a second leg."
