BALTIMORE — En route to last year’s World Series title, the Red Sox showed a fierce competitive nature. They simply didn’t like to lose, and that’s why they were a very happy group in 2013.

But the Red Sox also understand that losing is part of the game. No team is going 162-0.

That’s why the Red Sox were not throwing temper tantrums or going crazy after losing to the Orioles 2-1 on opening day Monday afternoon at Camden Yards.

The Red Sox certainly had their chances — but couldn’t come through.

Boston’s only run came on Grady Sizemore’s homer in the fourth inning.

The Red Sox had numerous chances, but went 0 for 10 with runners in scoring position and left 12 on base.

They stranded runners in scoring position in the second, third, sixth, eighth and ninth innings. Missed chances were the main subject of discussion afterward.

“We created a lot of opportunities, obviously,” Boston Manager John Farrell said. “We continued to create the chances. There was a lot of opportunities that we did create but didn’t cash in on.”

They also were hurt at times by Baltimore’s good pitching and defense. Left fielder Nelson Cruz made a nice catch early in the game, and Portland native Ryan Flaherty came up with back-to-back tough plays at third base that ended the sixth inning. Flaherty is filling in for Gold Glove winner Manny Machado while he’s on the DL recovering from knee surgery.

The various problems left Jon Lester with a loss despite a solid seven-inning effort. He gave up two runs and struck out eight, but the lack of offense handed him a tough loss.

Still, the Red Sox aren’t mourning.

“It’s tough when you lose any of them,” second baseman Dustin Pedroia said. “But you’ve got to find a way to play a little bit better. We’ll get back to work.”

Teams always enjoy opening-day festivities. Oriole Park at Camden Yards was sold out, and the 46,685 fans were cheering their team that they hope can give the Red Sox and Yankees more of a fight this year.

However, there were a number of Red Sox fans in attendance, something that’s common when the Red Sox visit.

A large group of Boston fans came down to the dugout after the gates opened three hours before the game, simply standing to try and get a look at the players as they came out for warm-ups.

There weren’t as many as normal because opening-day crowds are always heavy for the home team, but that solid group of Red Sox fans could be both seen and heard before and during the game.

One of the biggest positives for the Sox was Sizemore, back on the field after not playing since 2011 due to various health problems.

Sizemore singled on his first at-bat and then homered the second time up. His last home run came in July 2011, also in Baltimore, while playing for the Cleveland Indians.

“Today was very exciting,” Sizemore said. “I couldn’t wait to get to the ballpark. I was up first thing in the morning. I have a better appreciation just for the game and things that go into it.”

And in the end, the Red Sox understand all of that. They won the World Series last year and will always remember that experience, but a new season has begun.

This is the reason why, even though they lost a game they could have won, the Red Sox were simply looking forward and realizing there’s 161 more to play.

One game in March doesn’t make a season although winning would have been more enjoyable.

“We’ll get back out here Wednesday,” said first baseman Mike Napoli.

“Any game you lose is disappointing. But we’ve got a lot of games left.”