The midfielder has surpassed the Real Madrid icon's tally of 79 victories following the 3-1 triumph over AC Milan at Camp Nou
Lionel Messi scored from the penalty spot before Sergio Busquets doubled the hosts' lead, though Massimiliano Allegri's men were offered a lifeline from a Gerard Pique own-goal.
However, the Rossoneri failed the seize their chance at an unlikely point or three and Messi added a second goal to ensure the Blaugrana finished with a two-goal cushion.
Xavi was skippering the side in Carles Puyol's absence, playing in his 141st match (including qualification matches) in the elite European competition, and he expressed his joy at the three points gained over the Italian opposition.
"I'm so happy about the victory," he told reporters. "We did a good job, maybe we could have finished them off earlier, but they scored and we had to keep working hard.
"We can always improve, and we improved tonight - we saw a great Barcelona. Our philosophy is untouched, we want to win well and with good play.
"It was hard, because Milan were solid at the back. Messi is playing well, like the team are. He also can improve, he can always score more goals but he is doing fine."
The victory guarantees a spot in the last 16 for the Catalans as two of Celtic, Milan and Ajax cannot overtake Gerardo Martino's men.
Fellow Liga giants Atletico Madrid also sealed their place in the knock-out stages with a victory over Austria Vienna on Wednesday, while Real Madrid are expected to make it out of the group stages in the fifth gameweek later in November.