The win was Farrell's 400th as manager of the Red Sox.
The walk-off was also the 10th extra-inning win for Boston this season, which leads the American League.
The White Sox drew first blood, with Nicky Delmonico cranking a two-run, two-out double off of the Green Monster in the fourth inning to make the score 2-0.The rookie has been enjoying his time at Fenway this week, as he hit his first career home run on Thursday.
The Red Sox answered in the fifth and sixth innings, putting up a run in each to crawl their way back in the low-scoring affair.