McCutchen homered and reached base four times and the Pirates beat the Chicago Cubs 4-2 at rainy PNC Park on Wednesday night.
McCutchen is batting .462 during a seven-game hitting streak and has 12 extra-base hits during 10 June games.
"I don't compare (career-best stretches)," McCutchen said. "I'm not big on that. I'm just seeing the ball hitting the ball. I'm in a spurt where I'm feeling really good right now."
So are the Pirates, who have taken two of the first three games of the series with their NL Central rivals.
Pittsburgh's Brandon Cumpton (2-2) pitched five effective innings, and the offense pounded Cubs starter Jason Hammel (6-4) for 11 hits in five innings, snapping his streaks of 14 1/3 innings without allowing a run and 52 innings without allowing a homer when McCutchen hit his 10th in the first.
McCutchen also had a single and walked twice.
"He's hot," Pirates manager Clint Hurdle said. "When he gets his pitch, he's not missing."
Luis Valbuena likewise continued his recent strong hitting with three hits for last-place Chicago, which has lost three of four after a season-best five-game winning streak.
The game's first pitch was delayed 1 hour, 38 minutes because of a severe thunderstorm that began sweeping through downtown Pittsburgh about an hour before the scheduled start time. Rain fell again during the sixth inning.
McCutchen's fly ball landed more than a row into the left-field seats -- but it almost became an extra-long out when leftfielder Chris Coghlan leaped into the stands. He landed in the seats and said he had a read on the ball but that a fan outmaneuvered him for it.
"Best non-catch effort I've ever seen," Cubs manager Rick Renteria said.
"I would have went there and shook his hand myself if he caught that ball," McCutchen said.
The Pirates' Gregory Polanco went 1 for 5 with an RBI groundout a day after his much-hyped major league debut Tuesday.
Making his sixth start of the season and fourth since being given a regular rotation spot, Cumpton allowed two runs on five hits and two walks with five strikeouts. On his final pitch, he struck out Nate Schierholtz swinging with the bases loaded.
"It's something I need to work on, getting through the fifth and sixth innings," Cumpton said. "It was a good experience, a real confidence booster for me."
Hammel had won two previous starts against the Pirates this season and entered Wednesday with the second-best WHIP in the majors (0.88). He allowed 14 baserunners Wednesday.
"It was rough," Hammel said with a laugh. "A lot of hits given up. Up in the zone. Obviously could have been better strikes thrown, but I battled through. It could have been a lot worse -- 11 hits through five innings? It's amazing they only put up four."
Hammel was spared a worse line by some poor baserunning by Pittsburgh, which hit into two peculiar double plays and had another runner thrown out at third during the seventh inning after Hammel was out of the game.
The Pirates' Starling Marte had two hits -- including an RBI single in the fifth inning -- but also was thrown out on the basepaths for the third time in two games when he was picked off third following a Travis Snider pop-up behind home plate in the fifth.
The Cubs briefly tied the game at 2 in the second when John Baker's single drove in Valbuena and Nate Schierholtz scored on a groundout.
Before the game, the Pirates places LHP Francisco Liriano on the disabled list because of a strained left oblique that caused him to leave his start Tuesday in the fourth inning. . The Cubs on Wednesday announced they signed their first-round draft pick, Indiana University catcher/outfielder Kyle Schwarber. Schwarber, the No. 4 overall selection, will report to the organization's short-season Class A affiliate in Boise, Idaho. . Pirates 2B Josh Harrison was removed from the game for a pinch hitter during the third inning because of discomfort in his left ankle. . A fireworks display -- from the nearby annual Pittsburgh arts festival -- rumbled PNC Park for several minutes during the fourth inning. . Pittsburgh's Thursday scheduled starter, RHP Edionson Volquez, is 5-0 in his career against the Cubs. Chicago's probable starter, RHP Jeff Samardzija, has a 1.90 ERA in 71 career innings against the Pirates, including seven shutout innings on opening day at PNC Park.