The Sox have won three straight and are a season-best seven games over .500 (46-39) for the second time. They can sweep the series on Thursday afternoon with Nick Pivetta facing Kyle Tucker.
Bello (8-5) looked sharp on extra rest, allowing one run on seven hits over 6⅔ innings. He struck out seven and walked one, dropping his earned run average from 5.55 to 5.19.
Masataka Yoshida, the king of loanDepot park, was 2 for 4 with two RBIs and a walk. He is 8 of 16 with six RBIs in four games here counting the 2023 World Baseball Classic when he helped lead Japan to the championship.
Chris Martin pitched a scoreless eight inning to protect a 3-1 lead. He has not allowed a run in five appearances since coming off the injured list.
The Sox then put the game away with a four-run ninth inning, three coming on a double by Ceddanne Rafaela. The Sox finished with 12 hits. They are 36-4 when scoring at least five runs with 19 wins in a row.
Bello came into the game having allowed 22 earned runs in his five previous starts. He vowed that Wednesday would be the start of a new season for him but it was more of the same in the first inning.
Jazz Chisholm, Bryan De La Cruz, and Jesús Sanchez singled in the first inning as Miami took a 1-0 lead. Bello was able to limit the damage by striking out Jake Burger and retiring Xavier Edwards on a fly ball to center.
Marlins starter Tyler Rogers threw 84 pitches in the first three innings and put eight runners on base. But the Sox scored only two runs.
Both came in the third inning. Rob Refsnyder walked and Tyler O'Neill singled with one out. Rafael Devers singled to center to drive in Refsnyder and send O'Neill to third.
Connor Wong, who extended his hit streak 17 games with a single in the second inning, popped to shallow right field. Romy Gonzalez walked to extend the inning and a run scored on Masataka Yoshida's tapper to the right side.
Rogers had a play on the ball but couldn't scoop it up in time. The Sox had a chance for more but Dominic Smith struck out to end a seven-pitch at-bat.
The Sox stranded runners in scoring position in the fourth, fifth, and sixth innings against Huascar Brazoban.
Facing Calvin Faucher, the Sox loaded the bases in the seventh as O'Neill and Devers walked and Wong reached on an infield hit.
Gonzalez grounded to first and the Marlins got an out at the plate. Facing lefthander Andrew Nardi, Yoshida was able to drive in a run on a grounder to third base. That made it 3-1.
Bello retired 11 in a row, five by strikeout, before allowing two-out singles by Emmanuel Rivera and Nick Fortes in the seventh.
Sox manager Alex Cora had Brennan Bernardino ready for the lefthanded hitting Chisholm.