CHICAGO -- Brandon Belt felt like the Giants needed somebody to step up and be a leader, regardless of the fact that his team owned the best record in the Majors.

As San Francisco gets into the last few weeks of the season and into the end of the heat of a division race, Belt thought the team could use an "alpha" to lead the team through the end of the regular season. So he took it upon himself to name himself "captain."

"Really, it just started on the plane the other day," Belt said after the Giants' 6-1 win over the Cubs at Wrigley Field. "I just felt like, in my heart, I've been the captain all year, and so I just told everybody to let me get off the plane first since I was the team captain -- and they did. It's like, when people know that you're the guy, they don't say anything. They just do it."

With the victory in the series opener, San Francisco improved its record to a Major League-best 91-50 on the year, and the Giants lead the Dodgers (89-53) by 2 1/2 games in the National League West.

When Evan Longoria arrived at the ballpark for Friday afternoon's series opener, he decided to make Belt's new position official. He took black pieces of tape and made a "C" on the left side of Belt's jersey, an inside joke that most Giants thought would stay between them.

"Literally his locker is the first one in the hallway, so I saw that right when I walked in," said Kris Bryant, who made an emotional return to Chicago six weeks to the day after being dealt to San Francisco. "I thought for sure he would take it off for the game, because it's just some electrical tape."

"I put the 'C' on his jersey today… Not thinking that he was gonna go out and play with it," Longoria said.

But no, Belt didn't keep the joke inside the clubhouse. Instead, he made sure to keep his makeshift "C" on throughout the Giants' win.

"When I walked in and saw it, it was pretty funny," Belt said. "I was not gonna wear it, but everybody thought that I should. So, being the leader that I am, I stepped up and did it."

"I think he could have done a better job with the tape," Giants manager Gabe Kapler said. "It was sort of bootleg, but that's the only knock I have on it. Other than that, I thought it was a really fun, timely gesture. It was really good, really well played."

If Belt's performance on Friday is an indication of what he can do as the "leader" of the team, San Francisco might want to get a "C" stitched into his jersey every time he takes the field.

The Giants' bats were slowed by Cubs ace Kyle Hendricks out of the gate, with reliever Zack Littell's first career base knock in the top of the fifth making up half of his team's hit total to that point in the game. Belt, though, set a patient tone by reaching base in each of his three plate appearances against Hendricks, starting with a pair of walks in the first and third innings as he made up two of San Francisco's three baserunners early on.

When the Giants' lineup did get going, Belt was right in the middle of the action.

His leadoff double in the top of the sixth led to San Francisco's first score of the ballgame when Belt later raced home on LaMonte Wade Jr.'s RBI blooper, and four batters after Longoria's go-ahead, two-run shot in the seventh, Belt followed with a two-run homer of his own that broke the game open for good.

Though Belt's new title isn't one officially given to him by the team, Kapler appreciated the sentiment of him trying to keep things light as the final weeks of the season tick down.

"I think it's important to smile and laugh and be playful, right?" Kapler said. "This group takes each game very seriously. You can be playful and be intense. You can be playful and be a grinder. That is really who Belt is."

But is Belt truly the captain of this team?

"Brandon's the captain of something," Kapler said.