CHICAGO — It’s a part of the clubhouse celebration after every San Francisco Giants victory: Matt Chapman stands in front of the group, extols the performance of a teammate and awards him possession of an orange, pro wrestling-style championship belt.After Friday afternoon’s 18-3 victory over the Chicago Cubs at Wrigley Field, a game festooned with fruitful swings in which the Giants hit seven home runs, in which Willy Adames contributed a pair of two-run shots, in which Casey Schmitt went deep twice to put him on a pace to hit 38 (!!) this season, in which rookie Jonah Cox smacked the first homer of his career and in which Chapman compiled a sacrifice fly, a three-run shot and a grand slam while matching the San Francisco-era franchise record with eight RBIs, the title belt ended up in an unexpected place.With rookie catcher Daniel Susac. Who went 0-for-5.“For grinding it out and calling the right pitches,” Chapman said, smiling.Chapman has many attributes. An ironic sense of humor is among them, apparently.There’s also his Gold Glove defense at third base and his production at the plate, which goes in streaks that can be maddening at times. Yet he always seems to finish with numbers that are remarkably consistent from one year to the next.The first third of this season might have been the most maddening Chapman has experienced. The worst part was that he wasn’t going through it alone. The Giants had the lowest scoring offense in the major leagues through the middle of May, and the lack of steady production buried them in the standings.They are coming out of it now in no subtle way. Combined with the 12-9 pounding they gave the Milwaukee Brewers on Thursday, the Giants’ 30 runs over a two-game span are their most since the New York Giants did it in a doubleheader in 1944. They’ve combined for 39 hits over the past two games.The Giants still rank below average — 21st out of 30 teams — with 4.19 runs per game, which is a little hard to square when you take stock of a .260 average that ranks No. 2 (to the Los Angeles Dodgers). They also lead the league by a considerable margin with 132 doubles. They rank No. 2 in triples. And, no surprise, their six grand slams are the most in the league, too.They also continue to rank distantly last in walks, but they’re trending up in that category, too. The thought all along was that once their established core hitters started producing against pitchers who were pumping strikes with no fear, then the walks would come as opponents adjusted their approach.Well, they’re producing now. This was a team designed to win with an above-average offense. They’re finally rolling that design off the showroom floor.“We score a lot of runs, and it looks great on the scoreboard, but the quality at-bats everybody’s been taking down the line for the last couple weeks is probably what’s led to this,” Chapman said. “It’s been guys taking walks or working good at-bats, or Bryce (Eldridge) taking really good at-bats. Jung Hoo (Lee) comes back, and he’s hot. And even when we make outs, I feel like we’re being tough outs at the plate. That makes it fun. If one guy doesn’t do it, the next guy does it.”Chapman’s grand slam in the fourth inning, on a 1-0 curveball from Edward Cabrera, landed in the basket atop the ivy-covered wall in left field and came one day after Giants catcher Eric Haase hit one with the bases loaded in Milwaukee. It’s just the seventh time in franchise history that the Giants have hit grand slams in consecutive games, and, of course, the previous instance just happened on the last homestand when Harrison Bader and Rafael Devers hit slams against the Chicago White Sox.But wait! There’s more!Adames also hit a grand slam Sunday in Colorado, which means the Giants have joined the 2023 Houston Astros and the 1983 California Angels as the only teams to hit a grand slam in all three series of a three-city road trip.How’s this for a twist? Gary Pettis was the third-base coach for the Astros in 2023. He was a late-season call-up with the Angels in 1983. And Friday’s game was the first time he coached third base for the Giants, taking over for interim coach Ron Wotus after joining the team two days earlier in Milwaukee.“Damn show-off, isn’t he?” Wotus said.Adames gave the Giants a 2-0 lead in the first inning when he turned on Cabrera’s 99.5 mph fastball — the firmest pitch he’s hit for a homer in his career — and sent it to the back row of the left-field bleachers. Adames hit another two-run shot in a seven-run sixth inning, when the game turned from a blowout to ridiculousness. Three batters later, Chapman added his three-run shot.