CHICAGO -- There is likely no one who has been present for more pregame planning sessions with Jon Lester than David Ross. That made Monday's meetings strange for the Cubs' manager. 

After many years of working with Lester, both as the lefty's longtime personal catcher and then his manager, Ross was working with the Cubs on how to beat him. 

"It's extremely awkward," Ross said with a smirk. "When I start talking about my friend, you know, it's definitely the managerial seat, and our friendship creates a lot of conflict in my heart, for sure." 

In a 7-3 win, the Cubs achieved two goals: enjoying what was an emotional reunion with Lester and also flying a "W" flag atop Wrigley Field's old scoreboard. And Lester and former Cubs slugger Kyle Schwarber got their rousing, well-deserved standing ovations.

Lester was one of the leaders in the Cubs' rise out of rebuilding and to a World Series championship in 2016. On Monday night, the 37-year-old southpaw -- no matter the impact he made on the players in the home dugout and the fans in the stands -- was the enemy.

"When you face former friends and former teammates," Cubs first baseman Anthony Rizzo said. "You try to just kind of stick to your pregame routines and everything that you've leaned on your entire career. Just business as usual."

This was hardly business as usual, though.

Rizzo delivered the Cubs' first run in the first inning, when he sent a first-pitch fastball from his old friend to left field. In the grass in front of his old fans in the bleachers, Schwarber made the catch on what developed into a sacrifice fly.

From there, the Cubs launched three homers off Lester, who entered the night with a 2.25 ERA and no home runs allowed in 16 innings this season. That changed with blasts from Jason Heyward (second inning), Willson Contreras (third) and Javier Báez (sixth).

Ross, who caught 578 2/3 of Lester’s career innings, was not about to take credit for any insight he may have passed along before the game.

“That's all them. That has nothing to do with me,” Ross said. “These guys, I think that's just our offense. I think our offense has been doing that for a little while.”

Second on Lester’s career innings caught list is Contreras (548 frames). After Ross’ retirement from playing following the 2016 World Series triumph, Contreras began to learn and grow into an All-Star catcher and Lester’s primary receiver.

Contreras also cracked a smile when asked about preparing to face his old friend.

“I wanted to laugh. I wanted to smile,” Contreras said. “It feels strange facing him now that he's on another team. I wish him the best. We're still really close. We text each other back and forth once in a while. It was really good to see him back at Wrigley Field.”

With the Wrigley faithful on its feet, Contreras led off the game by sending a 1-2 cutter from Lester into center field at 107 mph off the bat, per Statcast. He later scored on Rizzo’s sacrifice fly. In the third, Lester fired a first-pitch cutter high and inside to Contreras, who pulled the pitch out to left field at 101.8 mph to put the Cubs ahead, 4-1.

"The one to Willy was kind of a back-up cutter that ended up middle,” Lester said. “Those ones, it doesn't matter if I'm facing a guy that I threw to for years. Those are the ones that get hit out.” 

Before that blast, Heyward launched his two-run shot in the second to the opposite field on a low-and-away fastball. 

“J-Hey, I kind of pigeonholed myself into that count,” Lester said. “Sometimes, you've got to tip your hat. He stayed on it, made a good swing and hit it out. I think that was more of a blow to me than the one to Willy.” 

Similarly, Báez attacked a 2-1 cutter that was over the outside edge of the zone in the sixth, sending it out the opposite way for a solo homer.

“Obviously I've seen Javy do it for years -- hitting the ball the other way,” Lester said. “But I felt like I had a good game plan against him, and I felt like I executed that pitch. And he just beat me to the spot." 

After Báez crossed the plate, Nationals manager Dave Martinez emerged from the visitors’ dugout to pull Lester. That ignited one final standing ovation -- the kind Lester missed out on in his last start as a Cubs last season. 

Lester kept his head down as he exited, making Ross wish the circumstances could still have been different for his longtime friend. 

“Jon rarely comes out of his character,” Ross said. “So I know he had to be torn. I'm sure, if you ask him, there had to be a lot of emotions going on. I was out there thinking we should petition the mayor tomorrow for Jon Lester Day.”