After Messi's 35th league treble, Barca boss Valverde hailed the 32-year-old star post-game at Camp Nou.
"Unbelievable," Valverde told reporters after Barca regained top spot ahead of rivals Real Madrid.
"It was a good way to celebrate the Ballon d'Or."
While Messi dominated headlines with his latest match-winning display, Barca team-mate Luis Suarez scored a stunning back-heel to round off a fluid passing move against Mallorca.
On Suarez's 43rd-minute goal, Valverde added: "The situation took me by surprise. I thought it was a pass to a team-mate.
"It surprised me, but it was an extraordinary goal. I told him that there had been a few easier chances and this one, which was improbable, went in."