With M. Licinius Crassus in command, the tide was about to turn in the Romans favor. Initially, an over eager subordinate of Crassus led an attack on Spartacus that failed miserably.
In this defeat several Romans fled the battle in the face of the gladiator army. In order to put an end to the terrible performance of the legions against Spartacus, Crassus ordered the seldom used penalty of decimation as punishment.
In decimation, one of every ten men is beaten to death by their own fellow legionaries. While ancient reports are conflicting, at least one full cohort was subjected to decimation, or possibly his entire force. Whether those put to death numbered around 50 men or 4,000 is in dispute, but there was no question among legionaries that Crassus was not a man to accept defeat with grace.
Crassus then moved his entire body against a detached segment of Spartacus' forces. With a full compliment of legionaries, Crassus wiped out 10,000 of the rebel slaves and moved against the main enemy body. Spartacus fled to Rhegium, across the straits from Sicily, with the hope of securing passage to the island, but was never able to secure passage with Cilician pirates.
Crassus pursued and built an extensive length of earthworks across the entire toe of Italy, trying to hem Spartacus in. At first Crassus was successful in trapping the slave army in, but the Senate viewed this as a demoralizing siege against an inferior foe. The great general Pompey was just returning from Spain, and they offered him an additional command to put an end to Spartacus once and for all.
Crassus was eager to achieve the victory himself and avoid sharing anything with his successful rival. He stepped up the pressure on Spartacus until he finally had little choice but to attempt a breakout. Unable to secure the passage to Sicily that he coveted, a breakout against the siege was ordered. While they did manage to escape, Spartacus lost a tenth of his army, or nearly 12,000 men. Free from Crassus' siege, Spartacus moved towards Brundisium, in the heel of Italy, where he still hoped to secure escape by sea.
The Romans were closing in, however, and an escape to Brundisium would never happen. Marcus Licinius Lucullus, fresh from a victory over Mithridates in the east, landed there with a full compliment of legionaries. Spartacus had little choice but to face his pursuers. Facing a full Roman army in open battle, especially one under adequate command, was something Spartacus tried to avoid, but in 71 BC, the slave army and the Romans met near Brundisium.
In the battle the inspired Romans dominated the slaves, and they were cut down in huge numbers. By the end, Spartacus himself was wounded and likely killed (his body was never found). Crassus swept survivors and stragglers out of the surrounding countryside by the thousands, and prepared a horrific, if not intimidating punishment. Up to 6,000 rebellious slaves were spaced out along the Appian Way, from Rome to Capua. Here they were crucified and left to rot as a reminder to all future potentials rebellions.
Pompey meanwhile had moved into Italy with his legions from Hispania. He swept out any remaining resistance and claimed final victory in the war. Pompey enjoyed a triumph for his 'victory' in Hispania, while Crassus was given the lesser honor of an ovation for his victory over mere slaves. The incident was an additional thorn in the side of a growing rivalry between Crassus and Pompey.
As the rivals stood on Rome's door step with full armies, both were elected Consul for 70 BC, despite Pompey's youth and lack of previous offices. Despite their rivalry, both men seemingly worked well enough together to repeal many of Sulla's unpopular laws. Pompey would soon be commissioned for further exploits in the east while Crassus would remain in Rome to continue amassing his fortune and influencing the politics of the 60's BC.