The battle of Saturnia (82 BC) was a minor victory for Sulla's forces over a detached part of Carbo's army during a period of campaigning in the area around Clusium (Sulla's Second Civil War).
At the start of 82 BC the two consuls for the year had split up, with Gnaeus Papirius Carbo heading north to deal with Metellus Pius and Marius the Younger going south to try and block Sulla. Marius suffered a defeat at Sacriportus and was besieged in Praeneste. This forced Carbo to abandon his campaign in the north and move back towards Rome, but Sulla was able to reach the city before him. The campaign then moved to the vicinity of Clusium, about 80 miles to the north of Rome. Carbo's main army was at Clusium, on the River Glanis. His lieutenant Carinnas had another force 40 miles to the east at Spoletium. Finally there was a detachment of troops at the spa town of Saturnia, 35 miles to the south-west of Clusium.
Appian reports three battles in quick succession. First Sulla defeated a detachment of cavalry on the River Glanis. Next 'Sulla overcame another detachment of his enemies near Saturnia'. Finally he fought a day long battle with Carbo at Clusium, but this ended inconclusively.
This would have been a rather unusual route for Sulla to take - north from Rome to the Glanis, then west/ south west across difficult terrain, and finally north-west across similar terrain to Clusium. A more likely suggestion is that Sulla himself advanced towards Clusium up the Tiber and Glanis, or the Via Cassia, while a second force was sent up the Via Clodia, which led from Rome to Saturnia.