NEW YORK -- The lure of a postgame concert by 1990s chart-toppers Boyz II Men drew 30,744 fans to Citi Field Saturday night. As far as the New York Mets were concerned, though, the headline act was Vic Black.

The right-handed Black inherited a bases-loaded, none-out jam in the seventh inning and needed just eight pitches to strand the bases loaded in the Mets' 7-3 win over the Chicago Cubs.

Black has now stranded the last 20 runners he has inherited and has stranded 21 of 22 inherited baserunners overall this season.

"He's been unbelievable," Mets manager Terry Collins said. "The job he's done to come in with guys on base is truly amazing. I mean, he has not flinched."

Black's success in such situations is particularly noteworthy given how wild he was in spring training. Black was expected to begin the season as the Mets' eighth-inning set-up man but he was demoted to Triple-A Las Vegas after walking a team-high 10 batters in 9 1/3 Grapefruit League innings.

"His command is 10 times better when there's guys on," Collins said. "I don't know if he's just so focused that he's got to get outs. But he's pitched brilliantly."

The latest Houdini act by Black may have been his most impressive. He entered after the Cubs pulled to 7-3 by scoring two runs on five straight hits off left-hander Jonathon Niese, who silently pleaded with Black as he watched from the dugout.

"Just please help me out," Niese said. "I was in a tough spot."

Black said his goal when he inherits such situations is allow no runs to score. When he received the ball from Collins at the mound, Black said Collins told him to get a ground ball -- to which Black gave his manager an incredulous look.

"I said 'Ground ball? That at best is a double play, and if it's not to home plate, that's a run scored,'" Black said. "I know what I would want (if) that's my run."

Black promptly retired left fielder Chris Coghlan on a fly to shallow left and second baseman Javier Baez and first baseman Anthony Rizzo on pop-ups to first base and shortstop, respectively.

"It's always cool to sit back and be like, man, I got out of that," Black said.

Niese was certainly appreciative of Black's rescue work as well as the sixth-inning outburst by the Mets, who scored four runs despite recording just one hit.

"I was fortunate Vic got out of it," Niese said. "Our offense did a great job putting up seven. Fortunate to get the win."

Niese (7-8) allowed the three runs on seven hits and two walks while striking out six.

The Mets led 3-1 entering the sixth, but Cubs right-hander Dan Straily had set down 12 in a row before plunking third baseman David Wright with one out. He allowed a single and two walks and was lifted after issuing a bases-loaded free pass to left fielder Matt den Dekker.

Center fielder Juan Lagares greeted right-hander Kyuji Fujikawa with a sinking liner to center, but the ball glanced off the glove of center fielder Arismendy Alcantara as two runs scored. Two batters later, Niese's groundout scored den Dekker.

Lagares had an RBI ground-rule double in the second and shortstop Wilmer Flores followed immediately with a two-run single for the Mets (59-65), who have won the first two games of the four-game series.

Wright left the game in the seventh inning with a sore left shoulder from the hit by pitch.

For the Cubs, catcher Wellington Castillo and right fielder Justin Ruggiano each hit solo homers while pinch-hitter Ryan Sweeney chased Niese with an RBI single.

Shortstop Starlin Castro's 14-game hitting streak ended with an 0-for-4 effort.

Straily, making his Cubs debut, gave up the seven runs (five earned) on four hits and three walks while striking out four over 5 1/3 innings. He was recalled from Triple-A Iowa before the game and is expected to be optioned back immediately afterward.

"I thought he was probably one hitter away from getting out of that (sixth) inning when he kind of mislocated and ended up hitting Wright," Cubs manager Rich Renteria said. "He was actually really close to getting out of that inning. Might have been a six-inning, three-run piece of work."

NOTES: To make room for RHP Dan Straily, the Cubs optioned OF Junior Lake to Triple-A Iowa. Lake was hitting just .216 with nine homers, 25 RBIs and 102 strikeouts in 291 at-bats. ... Cubs RHP Justin Grimm turned 26 Saturday. ... Mets RHP Jacob deGrom (right rotator cuff tendinitis) said he felt good after throwing Saturday for the first time since going on the disabled list Tuesday. The Mets hope he can come off the disabled list when eligible next Saturday. .. OF Chris Young, whom the Mets designated for assignment on Aug. 9, received his outright release after Friday's game.