FLUSHING, New York (Ticker) -- The Chicago Cubs still are waiting on Sammy Sosa 's 500th homer, but Mark Prior looks like he has arrived.

Prior pitched six strong innings and Moises Alou had a two-run double and drove in three runs as the Cubs defeated the New York Mets , 6-3.

The second overall pick in the 2001 draft, Prior (1-0) made his debut with the Cubs last season and split 12 decisions. The 22-year-old righthander made a solid impression on new manager Dusty Baker on Thursday, allowing one run, four hits and two walks while striking out seven.

"I've been impressed with him since the start of spring training, and he just seems to be getting better and better," Baker said. "He was tiring out there in the sixth, he threw a lot of pitches. But we wanted to get six out of him because our bullpen worked a lot of innings in the first two games of this series."

Seventy of Prior's 105 pitches were for strikes.

"I'm obviously more comfortable this year, knowing that I'm here at the start of the season," Prior said. "I know what my job is and I just take things start to start."

The Cubs won twice in three games at Shea Stadium, marking the first time they have taken a season-opening series since 1999.

But it came without a home run by Sosa, who has yet to homer this season and needs just one more to become the 18th player in major league history to reach 500.

Sosa had a pair of run-scoring singles in three at-bats and walked once, giving him six passes in the series.

"I feel the home run is going to come any minute. I'm just going to play my game and it's going to come. I'm not worried about it," he said. "I had my opportunities in New York and it would have been nice, but that's the way it goes.

"I hit the ball hard today, I knocked in some runs and we won. So I'm happy about that. All I can do now is pack my bags and go to Cincinnati and try to hit one in the new ballpark."

Former Cub Steve Trachsel (0-1) took the loss, allowing five runs and nine hits in five innings.

"I just got off to a rough start," he said. "When you put the top guys in the lineup on and you face Sosa and Alou, you're asking for trouble."

Trachsel picked off Corey Patterson and Mark Bellhorn in the second. The last pitcher to pick off two runners in the same inning was Tampa Bay's Joe Kennedy on April 29, 2002 against Minnesota.

Trachsel struggled in the first as Mark Grudzielanek doubled and went to third on a single by Alex Gonzalez . Gonzalez went to second on a wild pitch and both runners scored on a single to left field by Sosa.

The Cubs put together five straight hits in the third inning, scored three times, and could have had more if two runners were not thrown out at the plate.

Prior, Grudzielanek and Gonzalez singled to load the bases and Sosa drove in a run with an infield hit. Alou delivered a two-run double to left field but Sosa was thrown out at home. Alou was thrown out trying to score on a fly ball by Eric Karros to end the inning.

Trachsel has allowed 14 earned runs in 20 1/3 innings against his former team.

Prior was in control throughout as few Mets hit the ball solidly.

"He's tough. He's able to change speeds and is around the plate with all three of his pitches - fastball, breaking ball and changeup," Mets third baseman Ty Wigginton said. "The different velocities make him tough."

Kyle Farnsworth , Mike Remlinger and Dave Veres each pitched an inning to complete the victory.

Rey Sanchez drove in the first New York run with a groundout in the second.

Vance Wilson had a two-run single in the seventh to cut the lead to 6-3. Pinch hitter Mo Vaughn , who did not start due to a stomach virus, flied out off Veres to end the game.