Jones' four hits, Marshall's pitching power Cubs

" Hero: Marshall (2-2), who allowed only one run and one walk, striking out five.

" Boiling mad:
Arizona manager Bob Melvin was ejected in the seventh inning for arguing with the umpire over balls and strikes.

" Quotable: "If you want to call a game and a half breathing room -- my Lord, if we ever open up three.'' -- Lou Piniella, scoffing at a reporter's suggestion that Chicago has given itself some breathing room in the division.

-- ESPN.com news services

Cubs 6, Diamondbacks 2

PHOENIX (AP) -- Sean Marshall is enjoying his first pennant race.

Thanks to him, the Chicago Cubs opened up a little daylight between themselves and Milwaukee in the NL Central.

Marshall gave up one run in six innings, Jacque Jones had four hits and the Cubs defeated Arizona 6-2 on Friday night in a showdown of NL division leaders.

The Cubs increased their lead over the slumping Brewers to 1 1/2 games. Chicago has been in first for eight days, and Marshall (7-6) has contributed two victories during that span.

"It's fun," Marshall said. "Guys can compete and we have something to play for, unlike last year, when we were behind. This year, we've got a goal to achieve and hopefully we'll do it."

For the record, this is the Cubs' largest lead. But manager Lou Piniella scoffed at a reporter's suggestion that Chicago has given itself some breathing room.

"If you want to call a game and a half breathing room -- my Lord, if we ever open up three," Piniella said with a chuckle. "We've just got to play, really. At this time of the year it gets fun to watch the scoreboard a little bit. But boy, you'd better concentrate on what you're doing, because if not, you can lose ground awfully quick."

The left-handed Marshall (7-6) was a picture of concentration. He cruised through a lineup with eight right-handed hitters, allowing two hits in six innings. He walked one and struck out five.

"They came out aggressive, and it was to my advantage because they popped some balls up and got me some quick innings," said Marshall, who threw 72 pitches. "I pitched a little bit deeper in the game and it worked out well for us."

Arizona's lead in the NL West shrunk to two games over San Diego. The Diamondbacks have dropped four of five.

Arizona's frustration bubbled over in the seventh. Manager Bob Melvin was ejected in the seventh by home plate umpire Eric Cooper in an argument that erupted as Melvin returned to the dugout after replacing Owings.

"I just got frustrated with the strike zone," said Melvin, who was ejected for the second time this season. "He thought they were strikes. I thought they were balls. It just happens."

After the Diamondbacks pushed across a run in the ninth and put two men on, Ryan Dempster got one out in the ninth for his 21st save in 23 chances.

With throngs of vociferous Cubs fans invading Chase Field, the game had a playoff atmosphere. The Cubs have long had a devoted following in the Phoenix area, where they've trained since 1967.

Early on, the Cubs gave their fans plenty to cheer about. Micah Owings struggled through a 36-pitch first inning as the Cubs took a 2-0 lead on RBI singles by Derrek Lee and Mark DeRosa.

Owings (6-7) made it 2-1 in the third when he drove Marshall's first pitch 386 feet into the left field seats for his fourth home run, and his third in five at-bats. Owings homered twice in a four-hit game at Atlanta Aug. 18.

"That guy seems to be on fire right now," Marshall said.

That was the only hit Marshall allowed until Chris Snyder led off the fifth with a double. Snyder moved to third on a wild pitch, but shortstop Ryan Theriot nailed Snyder at the plate on a grounder to the hole to kill the threat.

"What a great play -- diving, accurate throw to home plate, and (Jason) Kendall did a nice job of blocking the plate," Piniella said.

The Cubs made it 3-1 on Aramis Ramirez' sacrifice fly to left in the sixth.

Owings gave up three runs on seven hits in six innings. He walked one and struck out two.

"I feel like I gave the team a chance to win and that's all I can concentrate on doing," said Owings, who has one victory in his last 12 starts.

Cubs scored three times in the ninth off reliever Dustin Nippert. Theriot and Jones had run-scoring singles, and another run scored on a wild pitch.

Game notes
Owings is the first pitcher to homer in back-to-back games since the Cubs' Carlos Zambrano, who did it on Sept. 17 and 23 last year. It's no surprise that Owings can hit. As a junior at Tulane in 2005, he was named to an NCAA Regional all-tourney team -- as a designated hitter. ... Craig Monroe, acquired from Detroit on Thursday, singled in the ninth in his first at-bat as a Cub. ... The Cubs are 15-3-2 in series when they win the first game and 2-17-2 when they lose it.