NEW YORK -- About the only nervous moment for CC Sabathia occurred when the large brace protecting his right knee fell off.

The rest of Wednesday night was stress-free for Sabathia and a reminder of some of the starts the left-hander used to deliver.

Sabathia won his fifth straight start by allowing five hits in eight innings, leading the New York Yankees to an 8-0 victory over the Boston Red Sox.

A strap on the large brace snapped after Sabathia retired Hanley Ramirez for the first out of the fourth and he pitched to three more hitters before it was replaced. He got a new one by the fifth, which began with a triple by Josh Rutledge but it also was the last Red Sox hit as Sabathia retired the last 12 hitters.

"I didn't know what to expect," said Sabathia, who has worn the brace since Aug. 2015. "I didn't feel any pain. I didn't feel any pain, so it was good."

Sabathia (7-2) won a fifth straight start for the first time since April 17-May 10, 2012, which was a year before a noticeable drop in velocity and a frustrating three-year stretch that saw him post a 23-27 record while getting right knee surgery in 2014 and dealing with alcoholism the following year.

He showed glimpses of past seasons at various points of 2016 by going 9-12 with a 3.91 ERA and started decently before allowing 22 runs in a span of four starts.

Since struggling in Cincinnati on May 9, the 2007 AL Cy Young award winner has lowered his ERA from 5.77 to 3.66. He struck out five without a walk and allowed two earned runs or fewer for the eighth straight time against Boston after throwing 64-of-95 pitches for strikes Wednesday.

"He's pitched really well this year," New York manager Joe Girardi said. "He had a few starts where had lost his command of his cutter and he found it again. It sets up everything for him but I think he takes a lot of pride in it. He's been that guy his whole career you can turn to when you needed a big win and he still does it."

It was Sabathia's 25th start without allowing a run in eight innings and his longest outing since April 20, 2015 at Detroit. It was his first start with eight scoreless innings since Sept. 21, 2012 against Oakland and it gave him his 230th career win.

"To me he didn't miss any over the middle of the plate," Boston center fielder Jackie Bradley Jr. said. "Everything was pretty much corners."

More importantly for the Yankees, Sabathia's performance occurred after a rough outing by Masahiro Tanaka. It was his fifth straight victory following a Tanaka loss and gave the Yankees something more pleasant to discuss than their No. 1 starter's woes.

"He's been holding us down the last three years," Sabathia said. "It's up to us as a staff to pick him up and we know that he'll come out of whatever he's in and he'll be fine for us."

Sabathia worked out of minor trouble all night, but his biggest play occurred after Rutledge tripled over center fielder Aaron Hicks' head. He speared a comebacker by Bradley with his bare hand on a ball clocked at 97.9 mph.

"That's a great play because that's probably a hit when you look at it," Girardi said.

Sabathia had a 5-0 lead through five innings on a three-run homer by Chris Carter, a solo homer by Didi Gregorius and a RBI single by Gary Sanchez. He finished the game up by eight runs after Matt Holliday, Carter and Brett Gardner added RBI singles.

Carter nearly had a second homer but right fielder Mookie Betts made a leaping catch at the wall after the ball went through the arms of a fan in the first row.

Most of New York's runs occurred against Rick Porcello (3-8), who is struggling to defend his Cy Young Award from last season. Porcello allowed six runs (five earned) and eight hits over 6 1/3 innings in his third straight loss.

Porcello yielded at least eight hits for the eighth time this season and leads the majors with 104 hits allowed.

"We have the ultimate confidence in him," Bradley said of Porcello.

NOTES: Yankees manager Joe Girardi said struggling RHP Masahiro Tanaka would make his next scheduled start Sunday against the Baltimore Orioles. ... The Red Sox announced RHP Brian Johnson will start Friday against Detroit. ... Boston LHP Eduardo Rodriguez (right knee subluxation) made throws from 120 feet without any physical issues. ... RHP Carson Smith, who is recovering from Tommy John surgery, threw about 20 pitches in a simulated game to 2B Dustin Pedroia and OF Andrew Benintendi. Smith will throw again Saturday and could start a rehab assignment sometime next week. ... New York LF Brett Gardner stole a base for the first time since April 10.