Luis Suarez scored a scintillating double and the returning Lionel Messi set up the winner as Barcelona came from behind to beat Inter Milan in a thrilling contest at Camp Nou on Wednesday.
Lautaro Martinez fired Inter ahead after just two minutes and Antonio Conte's side, mean in defense and ruthless on the break, looked capable of pulling off a historic victory in Group F.
But Suarez broke down the Italians' determined back-line with a stunning volley just before the hour and then finished off a weaving Messi run in the 84th minute to complete a pulsating 2-1 win.
Inter had never beaten Barcelona away from home in the Champions League but were the better side for long spells, particularly in the first half when they should have added to their one-goal lead.
Instead, Barca's deadly duo came up trumps again, Suarez breaking through just as the hosts looked to be running out of ideas before Messi, back from injury, teed up his partner for the decisive second.
Lionel Messi of FC Barcelona controls the ball under pressure from defenders of Inter during the UEFA Champions League group F match at Camp Nou in Barcelona, Spain, October 2, 2019. /VCG Photo
Inter play Juventus at home on Sunday, sitting top of Serie A after winning all of their six games so far and on this evidence, they could go far in Europe too.
Barcelona will be wary of the return fixture at the San Siro in December, which could yet decide who wins this group.
"Those are a big three points," said Suarez. "When you're the number nine, you always try to help the team with goals and assists. Sometimes it doesn't work, but I always work hard. Don't give up in difficult times."
Conte added: "This leaves a bitter taste because we deserved a lot more than we got. But congratulations to Barça, their stars (Suarez and Messi) changed the face of the match."
Salah hits double in narrow Liverpool win
Liverpool manager Jurgen Klopp believes the European champions have plenty of room for improvement after surviving a huge Champions League scare to beat Salzburg 4-3 after blowing a three-goal lead.
Sadio Mane opened the scoring against his former club before Andy Robertson and Salah put the holders in command inside the first 36 minutes before Salzburg bared their teeth.
The Austrian champions' teenage striking sensation Erling Braut Haaland was only fit enough for a place on the bench, but they still packed a punch going forward and were rewarded when Hwang Hee-Chan pulled a goal back just before half-time.
Takumi Minamino and Haaland, just four minutes after coming on as a substitute, then brought Salzburg level on the hour mark.
Mohamed Salah (R) of Liverpool and Dominik Szoboszlai of Red Bull Salzburg clash during the UEFA Champions League group E match at Anfield in Liverpool, UK, October 2, 2019. /VCG Photo
However, Salah had the final word as the Egyptian smashed home the winner 21 minutes from time.
"We opened the door and they were running through, chasing through the door," said Klopp.
"It's better to learn the lessons during the game than talk about it after it.
"It was a very important lesson for us to learn. I knew before we have to improve and now everyone knows."
Liverpool were under pressure to make fortress Anfield count after losing 2-0 to Napoli on matchday one.
Klopp's men lost all three of their away group games last season, but won all three of their home games to sneak through before going on to win the competition for a sixth time.
Other UEFA Champions League results on Wednesday:
Zenit 3-1 Benfica
Leipzig 0-2 Lyon
Valencia 0-3 Ajax
Lille 1-2 Chelsea
Genk 0-0 Napoli
Slavia Praha 0-2 Dortmund
(Cover photo via VCG)