The Nationals won their first series and are now 2-1 to start the season.
With the score tied at 4, Vidro took left-hander Rheal Cormier's 1-2 pitch over the left-field wall for his first home run of the season. It was his first long ball since Aug. 18 of last year against the Giants.
"I was trying to bunt to get on base because I saw the third baseman was back, but it didn't happen," Vidro said. "Cormier left the ball out in the middle of the plate. I was able to put a good wood on it. I was very happy."
Overall, Vidro drove in three runs in the game.
Nationals closer Chad Cordero pitched the final two innings and won his first game of the season. It's the ninth time he has pitched two innings or more since becoming the closer on June 8.
"That was a big game for us to win. It gets us over .500," manager Frank Robinson said. "We win the first series of the season. That's what we want to try to do -- win series. If we do that, we are going to be all right. It's a nice start to the season. It would have been disheartening if we had lost that ballgame."
Right-hander Esteban Loaiza started for the Nationals and gave up four runs in 6 2/3 innings. He struck out four batters and walked three. Loaiza flirted with a perfect game until it was broken up by Jim Thome in the fifth inning.
The Nationals gave Loaiza a 3-0 lead by the fifth inning against Phillies starter Randy Wolf. In the first, Vidro drove in Brad Wilkerson with a single to center field.
In the fifth, with runners on first and third and no outs, Wilkerson singled to right field to drive in Brian Schneider. For the game, Wilkerson went 4-for-5, a day after he hit for the cycle. In the series, Wilkerson went 9-for-14 (.643) with a home run and three RBIs.
"He's off to a tremendous start. He must be seeing the ball very well. He is in a good groove with his swing. He is hitting the ball all over the field, which is nice. It's tough to defense him," Robinson said. "I hope he keeps it going and he doesn't let (the media get to his head) and he doesn't read the papers."
Wilkerson said extra batting practice is the reason he is off to the best start of his career.
"For the work to pay off, it feels good. I have to continue to go up there and stay within myself. It feels good to get off to a great start -- for our team and for myself," Wilkerson said.
One out after Wilkerson's RBI single, Vidro hit a sacrifice fly to center field to bring home Loaiza.
Wolf pitched six innings and gave up the three runs on eight hits.
But the Phillies came back in the bottom of the sixth inning to tie the score at 3 against Loaiza.
With one out and Jose Offerman on first base, Placido Polanco hit a soft liner to center field for a base hit. Wilkerson tried to decoy Offerman into thinking that he was going to catch the ball. However, the ball went past Wilkerson for an error. Offerman scored all the way from first base and Polanco stopped at second
"You never know what's going to happen out there. I was just thinking about getting people out. I was concentrating on the next hitter," Loaiza said. "The ball had a good spin and it took off. Other than that, I was pitching my game and I got a little wild."
After Bobby Abreu walked, and Jim Thome was hit by a pitch to load the bases, Pat Burrell singled up the middle to score Polanco and Abreu.
"Loaiza was fine. It wasn't all his doing either in that sixth inning," Robinson said. "Loaiza was sailing along very nicely. He pitched a tremendous ballgame. He did very well. I'll take that. He looked at home out there. He moved his pitches around in the strike zone. He kept the hitters off-balance. He kept us in the ballgame."
The Phillies then took the lead off Loaiza in the bottom of the seventh inning, when Polanco singled to left-center field to drive in David Bell.
But the Nationals tied the score at 4 in the top of the eighth inning off reliever Tim Worrell.
Jose Guillen led off with a triple. Nick Johnson then hit a hard grounder that bounced off the first-base bag. Thome managed to get Johnson at first but Guillen scored easily.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.