The rookie right-hander pitched seven shutout innings in the longest outing of his career, and New York beat the Chicago Cubs 6-2 on Friday night to win consecutive games for the second time since July 30.
"I just told myself to go out there and have fun and go after hitters and whatever happens, happens," Parnell said. "I was able to have my stuff tonight and was able to go after them."
Cory Sullivan homered and made a diving catch in left field for the injury-ravaged Mets.
Parnell struck out seven and walked three. He allowed five hits and escaped a bases-loaded, none-out jam in the seventh.
"It's good to see the mental toughness," teammate David Wright said. "That just shows the maturing process. There's been a tendency when he struggles to let the floodgates open. Today he put a stop to that."
It was an encouraging performance for the fourth-place Mets, auditioning Parnell for a 2010 starting role as they play out the string this season. The hard-throwing right-hander, who spent much of the year in the bullpen, was roughed up in his previous three starts, including last Saturday by the Cubs at Wrigley Field.
"I think I'm more acquainted with starting. I want to probably pursue that a little bit more," Parnell said. "It's going to be a time to develop and a time to gain some confidence and just learn how to pitch in the major leagues as a starter. Just try to take something and learn something every day."
Carlos Zambrano delivered a solid outing for the Cubs, allowing only Sullivan's solo homer in six innings. The big right-hander yielded three hits and struck out seven, but is winless in five starts since July 22.
The Cubs began the day six games behind NL wild-card leader Colorado.
"We're running out of time. We need to play better and do a better job -- everybody," Zambrano said.
"We had chances and we didn't take advantage. They had chances and they did," Chicago manager Lou Piniella said. "It's gotten beyond the point of frustration. I don't know what you do."
Before the game, Piniella revealed that left fielder Alfonso Soriano is out indefinitely with a sore left knee.
In the second inning, Sullivan hit his first homer since Sept. 12, 2007, with Colorado. His drive to right reached the railing above the facade of the second deck at spacious Citi Field.
Sullivan also made a terrific grab in the fifth, robbing Kosuke Fukudome of a hit.
With the score tied at 1 in the eighth, Luis Castillo beat out an infield single. Wright, who struck out his first three times up, singled to left-center off Kevin Gregg (5-6), sending Castillo to third.
Tatis put New York ahead with an opposite-field single to right off left-hander John Grabow.
"I have not pitched good at all this year. It's not fun," Grabow said.
Mets CF Carlos Beltran (knee) played seven innings in center field and went 0-for-3 in a rehab game with Class-A Brooklyn against Lowell. He is 1-for-8 with an RBI and two walks in three games at Brooklyn. ... Sullivan also walked twice during a perfect night at the plate. ... Cubs starting pitchers have a 0.32 ERA in the last four games. They've allowed one earned run in 28 innings. ... Cubs 1B Derrek Lee missed his second consecutive game to be with his wife, who gave birth to their second child early Thursday morning. Piniella said he expected Lee back on Saturday. "I hope he remembers it's a day game," Piniella said, laughing. Micah Hoffpauir started at first base. ... The Cubs recalled infielder Bobby Scales from Triple-A Iowa and claimed right-hander Thomas Diamond off waivers from Texas. ... Baker went 3-for-3 with a double.