BOSTON -- Red Sox flame-throwing righty Nathan Eovaldi came out throwing smoke in the Red Sox's 13-2 rout of the Orioles on Opening Night.

His first pitch of the season purred in at 99.6 mph.

By the time Eovaldi stepped to the mound for the top of the third on Friday at Fenway Park, it appeared half of his number disappeared from his jersey.

Eovaldi normally wears No. 17. But starting with that third inning, he was wearing No. 7, which was also the number that his batterymate Christian Vázquez had on.

Judging by the fact that the No. 7 was smack in the middle of Eovaldi's back, it was obvious that it was a new jersey rather than the one he started the game with.

So what gives?

"Yeah, so I guess Vazquez and I both sweat a lot so we had the jerseys hanging down in the batting cage," said Eovaldi. "I didn't realize his were down there, too. I glanced over and saw the No. 7, thought it was mine and grabbed it off the hanger, threw it on. And once I came back through the dugout [after finishing the third inning], they were like, 'Atta boy, Vazqyy!' I was like, 'What?' They were like, 'You have his jersey on.' I was like, 'I thought it felt a little tight on my arms,' but it's all good."

By the fourth inning, Eovaldi was back to wearing his No. 17 jersey and cruising with a 10-0 lead.

It didn't matter which jersey he was wearing, to tell you the truth. The righty was strong in the first Opening Day nod of his career, allowing one run over six innings while walking one and striking out four.

"Any time you can get a win and watch Nate throw the pill the way he did, it was fun to play behind him tonight," said Red Sox center fielder Jackie Bradley Jr.