Butler, who was coming off two mediocre performances in two Miami losses, played on Saturday at a stratospheric level adding 35 points and 12 assists without committing any turnovers, figures that no one had achieved in the NBA with a 75% effectiveness in field shots (12-16).
The recital of the veteran escort ruined the titanic effort of Luka Doncic, who signed 42 points, 10 rebounds and 8 assists.
It is the second time in the campaign that the Slovenian exceeds forty points but cannot avoid a loss by Dallas.
Irving, the star arrived in February to propel Dallas into the playoffs, finished with 23 points and 8 assists.
The Mavericks have lost six of their last seven games and, with just four more on the regular season schedule, they are 11th in the Western Conference and provisionally out of the playoffs.
The young Oklahoma City Thunder, a team in full reconstruction, are located in tenth place, the last one that gives access to the playoffs, with one more victory than the Mavericks, who also have the tiebreaker factor against them.
The Heat, on their side, are seventh in the East and will try to climb one more step and secure a direct place in the playoffs.
In the other game on Saturday, the New Orleans Pelicans beat the Los Angeles Clippers 122-114 in a stellar duel between forwards Brandon Ingram and Kawhi Leonard.
Ingram commanded with 36 points the victory before his public of the Pelicans, who overtake the Los Angeles Lakers and are in seventh position in the West.
On his side Leonard, who for the first time this season competed on two consecutive nights, signed 40 points and 8 rebounds, forced to multiply by the injury of his partner Paul George.
The Clippers fell to sixth place in the West where they will try to resist the stalking of the Pelicans and Lakers.
– Results of Saturday in the NBA:
Miami Heat – Dallas Mavericks 129-122
New Orleans Pelicans – LA Clippers 122-114