Shane Bieber pitched two-run ball into the eighth inning, and the Cleveland Guardians beat the Chicago White Sox 4-2 on Thursday night for a three-game series sweep.

Cleveland opened a seven-game lead over Chicago in the AL Central with its 15th win in 18 games. The Guardians (83-67) can clinch the franchise’s first division title since 2018 as early as Sunday.

Bieber (12-8) earned his fourth straight win. The 2020 AL Cy Young Award winner allowed seven hits, struck out five and walked none in 7 2/3 innings.

“Like a lot of good pitchers, he kind of worked into finding his stuff,” Guardians manager Terry Francona said. “He kind of pitched himself into looking like Bieber, which is pretty impressive.”

Trevor Stephan finished the eighth and Emmanuel Clase handled the ninth for his AL-best 37th save in 41 chances