"Yeah, he was erratic," Red Sox manager Alex Cora said. "It wasn't a good one. We know it -- it's going to happen. He's going to have one of those: We turn the page. And he's going to get his turn the fourth game after the All-Star break. He'll be OK."
Boston did maintain its 3 1/2-game lead in the American League East, thanks to the Yankees losing in Cleveland.
In his shortest start since July 29, 2015, Porcello (11-4) went just two-plus innings, getting tagged for seven hits and eight runs. Normally a control specialist, Porcello walked a season-high four and struck out only two. It was just the fifth time in his last 86 starts Porcello has logged fewer than five innings. His ERA jumped from 3.58 to 4.13.
"Just never got into a groove, walked four guys, can't expect to have success when you put four guys on base," Porcello said. "Free passes, and [I] just couldn't make pitches with those guys on base. I never found it. I don't know what to say really; this one's completely on me."
Mookie Betts electrified the Red Sox early, belting triples in each of the first two innings. The second triple just missed being a homer, but it drove in two of the five runs Boston scored in the bottom of the second en route to a 6-3 lead.
That lead was short-lived, and so was Porcello's night.
The Blue Jays answered Boston's five-spot in the third with a big frame of their own. Justin Smoak opened the inning with a home run. Kevin Pillar (two-run double) and Dwight Smith Jr. (two-run homer) knocked Porcello out of the game and made it 8-6 in Toronto's favor.
"Our team did a hell of a job putting up [five] runs after I put us in a deficit, and I couldn't hold it," Porcello said.
Porcello had no inkling that this would be a tough night.
"No, I felt pretty good [beforehand], honestly. All week I felt good. I had some things I was building off of that felt good in the delivery, and got out there and it wasn't the case," Porcello said. "It's hard to explain sometimes, but I know I've got to be better, and I will, and I'll move on from it."
The Red Sox got one back in the fourth on an RBI single by Mitch Moreland.
But they couldn't draw any closer, and the Blue Jays broke it open against Joe Kelly and Robby Scott in the eighth. Kelly threw eight pitches and didn't retire any of the three batters he faced. After a shaky June, Kelly had started to settle in of late, but he took a step back in this one.
All in all, it was a loss the Red Sox could quickly put behind them considering how well things have gone lately.
"It's just one of those games," slugger J.D. Martinez said. "Usually you don't see Ricky get hit that hard. Obviously it wasn't his day, but Ricky works hard and I'm sure he'll come back next start and pitch well."
MOMENT THAT MATTERED The Red Sox traded for reliever Tyler Thornburg on Dec. 6, 2016, but due to a litany of injuries, he didn't step on the mound for a home game at Fenway Park until Friday, when he pitched a scoreless fifth inning, striking out two and allowing just an infield hit.
Thornburg threw 25 pitches, and one of them was 95.5 mph. It was the best of his three outings since he came off the disabled list.
SOUND SMART Betts is a force everywhere, but this is particularly true at Fenway Park, where he is hitting .409 with a .493 on-base percentage and a 1.301 OPS. Those marks lead the Majors for any players with at least 100 plate appearances in home games this season.
HE SAID IT "Not too difficult -- we're playing good baseball right now. We just came off a 10-game win streak. I had a terrible night, that's for sure. But at the same time, our ballclub is playing well right now and I'm not going to let one bad night affect what we're doing. Keep moving forward." -- Porcello, on whether the tough start would be hard to shake off
UP NEXT Eduardo Rodriguez (11-3, 3.62 ERA) will try to end his strong first half on a high note when he pitches Saturday's 1:05 p.m. ET contest against the Blue Jays. The lefty has won his last two starts, allowing no runs over 11 2/3 innings. Rodriguez is 3-3 with a 5.09 ERA lifetime against Toronto, which will counter with right-hander Sam Gaviglio (2-3, 4.70).