The 25-year-old started the bout in dominant fashion as he displayed his power with several shots to the body, but Guerrero responded with a couple of strikes at the first-round bell.
Thurman's attempts to take the fight to the 31-year-old almost cost him as Guerrero landed a punch which caused a lump to appear over his left eye.
However, Thurman was undeterred by his injury and rallied by landing several quick shots to the chin, which appeared to unsteady Guerrero momentarily.
The 25-year-old began to up the ante as the fight progressed and he made his biggest impact in round nine as he dropped his opponent with a huge right hand to leave the 31-year-old on the mat and bleeding from his eye.
Guerrero managed to hang in the fight and went blow-for-blow with Thurman in the 10th, before his opponent landed three uppercuts to take the bout out of his reach.
The 31-year-old tried to get himself back in the bout late on, but Thurman kept himself out of trouble as the judges highlighted his controlling display with scores of 120-107, 118-109 and 118-108.