Gavin Williams closed out Game 4 of ALDS. He's also starting Guardians-White Sox rubber match

Before Thursday night, Gavin Williams hadn't registered a relief appearance in his professional career. The 27-year-old right-handed ace was called upon to shut down a last-ditch effort from the Chicago White Sox in Game 4 of the American League Division Series.

Williams relieved closer Cade Smith, who gave up a solo shot and a walk to start the bottom of the ninth inning after spinning a scoreless frame in the eighth after two shutout innings the previous day in a Game 3 Cleveland victory.

Although Williams conceded a single to the first Chicago batter he faced, he regrouped and dashed the hopes of the South Siders, swiftly ending a potential comeback bid and extending the White Sox's 120-year drought without a postseason series-clinching win at home. Williams sealed the 9-5 decision, the Guardians' second consecutive road triumph after beginning the ALDS with back-to-back defeats.

Two days later, the 6-foot-6, 250-pound hurler will have to come up big for the Guardians again, as he's remaining the team's pick to start a winner-take-all Game 5 against the White Sox. Williams, this season's AL strikeout leader , will get the nod with a chance to face the Tampa Bay Rays in the AL Championship Series on the line in Cleveland.

"It's a Game 5, win or go home," Guardians manager Stephen Vogt said Friday, per MLB.com . "Gavin wants the ball. We want him to have the ball, and it's his game."

Granted, Thursday was a scheduled throw day for Williams anyway, but his emergency relief appearance made for an unorthodox between-starts bullpen session. Game 4 saw Guardians left-handed starter Parker Messick last just 2 1/3 innings. Vogt had to go to his bullpen early. And, ultimately, he needed more help to wrap things up after Smith's fatigue seemed to show in the ninth.

Fortunately for Cleveland, Williams managed to keep his pitch count relatively low, needing only 18 pitches to record three outs and finish out the series-extending win. He also started Game 2 of the ALDS on Monday, dazzling with 11 punchouts . That said, in a 4-3 loss, he allowed three walks and four hits and was accountable for two runs across five innings of work.

The upstart White Sox have embraced unconventional pitching plans throughout their feel-good postseason run. But on Saturday, they'll be handing the ball to right-handed starter Sean Burke.

Burke, like Williams, also pitched in Game 2. He entered that matchup during the third inning and went 5 1/3 innings, surrendering one hit, one walk and one earned run while logging six K's.

The White Sox used seven pitchers in their Game 4 loss, including closer Grant Taylor. The righty was roughed up in a doomed sixth inning that consisted of six Guardians runs.

A day of rest is helpful for both teams' pitching staffs. The White Sox narrowly edged the Guardians in the regular-season series, 7-6; however, Cleveland wound up wearing the AL Central crown.

The division foes are taking the ALDS down to the wire, too, with Williams and Burke getting the first stab at the showdown on the mound.