diff --git a/superset/commands/chart/create.py b/superset/commands/chart/create.py
index 84b3aa29411e..e3d3ea93f330 100644
--- a/superset/commands/chart/create.py
+++ b/superset/commands/chart/create.py
@@ -34,6 +34,7 @@
 from superset.commands.utils import get_datasource_by_id
 from superset.daos.chart import ChartDAO
 from superset.daos.dashboard import DashboardDAO
+from superset.utils import json
 from superset.utils.decorators import on_error, transaction
 
 logger = logging.getLogger(__name__)
@@ -43,6 +44,13 @@ class CreateChartCommand(CreateMixin, BaseCommand):
     def __init__(self, data: dict[str, Any]):
         self._properties = data.copy()
 
+        if params_str := self._properties.get("params"):
+            params = json.loads(params_str)
+            if isinstance(params, dict) and "viz_type" in params:
+                # Only fall back to params when no top-level viz_type was supplied;
+                # an explicit top-level field takes precedence.
+                self._properties.setdefault("viz_type", params["viz_type"])
+
     @transaction(on_error=partial(on_error, reraise=ChartCreateFailedError))
     def run(self) -> Model:
         self.validate()