Democratic presidential nominee Joe Biden’s campaign decided to do some counterprogramming on Thursday night by debuting a new two-minute ad on broadcast and cable TV during the final night of the Republican National Convention. President Donald Trump’s favorite cable news channel, meanwhile, ended up airing the spot while Trump’s social media guru was delivering his RNC speech.

As Trump aide Dan Scavino took the stage, Fox News pulled away for an ad break, including Biden’s commercial that portrayed Biden as spry and vibrant while a narrator says: “When Joe Biden is president, America is just going to have to keep up.” The ad also heavily trolls Trump, poking fun at the president’s infamous slow ramp walk as the narrator says that some people “race up steps when others take it slow.”

Fox News did eventually air the very end of Scavino’s speech—only after Biden’s ad ran in full.