BOSTON -- Giancarlo Stanton had been looking forward to a memorable introduction to the sport's greatest rivalry, digging into the ancient Fenway Park batter's box with an interlocking "NY" on his helmet. As the evening careened out of control, the star slugger and his teammates swiftly tried to forget this one ever happened.
Mookie Betts' monster performance came at Luis Severino's expense on a bumpy night for the right-hander, who was already in the clubhouse when Boston batted around for a nine-run sixth inning. The Red Sox rolled to their ninth straight victory on Tuesday, a 14-1 drubbing of the Bombers.
The contest marked the Yankees' most lopsided loss to the Red Sox since Aug. 22, 2009, when they fell by the same score on the same patch of real estate.

"Just a crappy night all around," manager Aaron Boone said.
Aaron Judge was a bright spot, homering among his three hits off left-hander Chris Sale, who otherwise handcuffed the Yankees with eight strikeouts over six innings to pick up his first victory. Judge singled in the first and third innings before crushing a 444-foot blast to center field in the fifth inning.
"It was a tough game, a tough loss," Judge said. "Nothing was really working for us. We weren't able to string a couple of hits together off Sale tonight, and that's tough. One of the best pitchers in the game, you've got to be able to manufacture some runs and put a couple on the board early. We weren't able to do that tonight, and they were able to do it against Sevy."
Severino said that he left his slider over the plate too frequently, and there were suggestions that Severino may have been tipping his pitches. If so, the loaded Red Sox offense took advantage. Peppered for five runs and eight hits in five innings, it marked just the Yankees' third loss in Severino's last 18 regular-season starts.
"I saw a lot of balls that showed up in the middle of the plate," catcher Austin Romine said. "When you throw some balls in the middle of the plate against a good-hitting team like this, they're going to make you pay for it."
Betts went 4-for-4, reached base five times, scored five times and launched a grand slam. Betts became the first Red Sox player to have four hits, four runs and four RBIs in a game against the Yankees since the RBI became an official stat in 1920.

Beating up on Tommy Kahnle and Chasen Shreve, Boston scored nine runs on three hits in the sixth inning, including Betts' third career grand slam and a two-run double to center by J.D. Martinez. Andrew Benintendi (triple, double, two runs, two RBIs) and Hanley Ramirez (three RBIs) also fattened their numbers against New York hurlers.
MOMENTS THAT MATTERED
In the hole early: Severino's pitch count escalated quickly through the first two innings, with Boston jumping out to a 4-0 lead. After Severino escaped a bases-loaded jam with one run in the first inning, Benintendi bashed a two-run triple and Ramirez fought off a 98.9-mph heater from Severino for an RBI single to left that boosted Boston's lead to four runs.

"I don't know if I was tipping or they saw something, but the game is not the time to work on that," Severino said. "I need to maybe go to the bullpen or see video, and see what's going on. After that, maybe I'll work a little bit on that."
No relief: Down by three runs after Judge's homer, the wheels came off for the Yankees in the ugly nine-run sixth inning. Kahnle's outing in particular concerned the Yankees, as the right-hander's fastball velocity and command have been absent, leading to his swollen 7.11 ERA. Kahnle's average fastball velocity was 97.9 mph last year, but he averaged 93.9 mph in Tuesday's outing.

"I'm not worried. I'm just more trying to figure out what's wrong at this point," Kahnle said. "I think it's mechanical. I've been all over the place a little bit lately. … It's a long season and we're going to have our ups and downs. I just think right now we're scuffling. It's OK. We're going to pick our heads up and get back at it."
QUOTABLE
"It was cool. Not a cool outcome, but it was cool to see the passion and what goes on." -- Stanton, on playing at Fenway for the Yankees
SOUND SMART WITH YOUR FRIENDS
The nine runs allowed by the Yankees in the sixth inning were the most since the Rangers posted a 10-run third inning on May 23, 2015.
WHAT'S NEXT
Masahiro Tanaka will make his third start of the season on Wednesday at 7:10 p.m. ET as the Yankees and Red Sox face off for the second game of this three-game set. Tanaka is 7-4 with a 3.65 ERA in 14 career starts against Boston, and 2-1 with a 3.35 ERA in seven starts at Fenway.
Watch every out-of-market regular-season game live on MLB.TV.