The Myth: "Messi completed a world record 23 successful dribbles vs Villarreal in the Copa del Rey in 2008"
This is a common myth on social media and has its origins on YouTube. Somebody uploaded a video with the title "Lionel Messi - 23 Dribbles in One Game | WORLD RECORD". However, the dribbles were simply counted by the creator of the video - this isn't "wrong" but it means the dribbles do not follow the most widely accepted successful dribble criteria (Opta's), so the number loses its meaning.
Of course, anyone is free to watch a video and apply their own criteria, but that number cannot then be compared to other dribble stats that are from Opta. And you definitely couldn't claim it to be a "world record".
As per this AS.com article, the actual number of Opta successful dribbles in this game is 18 (from 24 attempted), which is the highest on record for Messi in a single match.
The Myth: "Ronaldo completed a world record 20 successful dribbles vs Benfica in the Champions League in 2006"
This is by far the most prominent and relentless myth in the Messi/Ronaldo world. It originated in the same way as the previous Messi dribbles myth (on YouTube), but it gained mainstream traction in a way the Messi version hasn't, despite the real number being much easier to verify. It's actually a perfect example of how fake news can snowball on the internet.
Somebody uploaded a video to YouTube titled "The Match Where Ronaldo Completed 20 Dribbles!", in which, again, the dribbles were simply counted by the video creator. The video was then shared a lot on social media, and was soon picked up by sites like SportBible and GiveMeSport, who create articles out of viral posts that can get them clicks. These sites have large followings and significant traffic, but they are not particularly concerned about fact-checking.
Opta confirmed several years ago that the correct number of successful dribbles for Ronaldo in that fixture is actually 14 (from 21 attempts), and the full data has since been added to SofaScore, eliminating any lingering doubts.
This is the highest on record for Ronaldo in a single match, and is among the highest ever in the Champions League.