SAN FRANCISCO - If it wasn't for Hunter Pence, Cliff Lee may have very well shut out the San Francisco Giants on Monday night.

In his first game against his former team, Pence tried to be a one-man wrecking ball in the Giants' lineup. He homered in his first at-bat and attempted to start a rally with an eighth-inning, leadoff double in his last at-bat.

He went 3-for-3 and scored the only two runs San Francisco scored in a 6-2 defeat to the Phillies.

"He looked good," manager Charlie Manuel said yesterday afternoon at AT&T Park. "I'd say he hit the ball about as hard as you can hit it."

Pence was back in rightfield last night for the Giants.

He has started all 33 games this season. He entered last night hitting .297 with a .331 OBP, an .847 OPS, six home runs and 20 RBI.

The Phillies, by comparison, got the following production from their array of rightfielders through the season's first 5 weeks: They've hit .171 with a .279 OBP, .555 OPS, one home run and six RBI.

Their rightfielders rank last in the National League in four of those five categories.

So it was fair to ask Phillies general manager Ruben Amaro Jr. if he regretted dealing away both Pence and Shane Victorino 2 days before the trade deadline last July.

"Still really happy with them," Amaro said. "They were the right things to do for us . . . Based on where we were last year, and what having both of those players on our club would not have allowed us to do, I think they were the right things for us. And I think it was the right things for the players, too."

Victorino was entering free agency; he cashed in on a 3-year, $39 million deal with Boston. Pence, who will become a free agent for the first time after this season, is making $13.8 million in 2013.

Amaro obviously felt it was more important to use those dollars to fill holes at third base and in the bullpen, with Michael Young and Mike Adams. He has no regrets.

The trade also worked out OK for Pence: He lifted a World Series trophy over his head less than 3 months after the Phillies sent him to San Francisco.

But the transition wasn't an easy one, Pence said before taking batting practice yesterday. Pence said his first reaction after being traded was that he felt like he let the Phillies down.

"To be honest with you, I felt really guilty," Pence said. "I felt like I did something wrong. Obviously I shouldn't have looked at it that way, it was the wrong way to look at it. But I was heavily invested in bringing the Phillies back, and it felt like . . . I felt guilty. I felt like it was my fault that it fell apart."

The Phils had the best record in baseball when Pence arrived from Houston in July of 2011. When Pence left 12 months later, the Phillies were 12 games under .500 and in last place.

Of course, the 2012 season began with both Ryan Howard and Chase Utley on the disabled list; Roy Halladay would join them in the season's second month.

Pence admitted he tried to do too much in their absence.

"That's 100 percent what I did," Pence said. "And in this game, I say it a lot: You can't try; you've got to trust. And I was trying to make it happen. But there was a great lesson for me in that experience, there was a letting go. There was a lot I had to learn."

After hitting .324 with a .954 OPS and 11 home runs in 54 games after arriving from Houston, helping the Phils win a franchise-record 102 games, Pence struggled in 2012. He hit .271 with a .784 OPS before being traded to the Giants.

Pence said he was "shocked" at the time of the trade, but he spoke with Amaro before Monday's game and appreciated his old boss' congratulatory handshake for last fall's World Series victory.

"When he traded me, the phone conversation was one of the nicest things I've ever heard," Pence said. "It was hard. He told me, 'We love you.' That to me in itself - there were other things said - but that to me, you're very grateful for that.

"I loved my time in Philly. It's been said. I had a lot of fun there. I was heavily vested there. That's why I did feel so guilty when I was traded. And to be honest, it didn't leave me for a while. It's just my nature. I put the weight on my shoulders, the weight of the world, and I shouldn't have done that."

The hangover of the trade took effect upon Pence's arrival in San Francisco: he hit .219 in 59 games.

But once the postseason began, Pence and a group of veterans that included infielder Marco Scutaro and reliever Javier Lopez became the vocal presence that helped the team rebound from an 0-2 deficit in the NLDS against Cincinnati.

After hitting .171 with no extra-base hits in his first nine games of last postseason, Pence went 2-for-5 with two RBI in San Francisco's 9-0 win over St. Louis in Game 7 of the NLCS. He hit .286 in the Giants' four-game sweep over Detroit in the World Series.

Pence was asked what made him turn into the Giants' pregame cheerleader, pumping the team up with chants, before those playoff games.

"It was a combination of several things," Pence said. "We had a similar thing, there was a quietness around the clubhouse after we lost the first two games as there was when I was in Philly and we lost Game 4 in St. Louis. There was a weird quietness. Everyone looks like, 'Yeah, we believe, we believe.' . . . It was a collection of all of us, I just happened to be the speaker. And it worked out the way it did. Everyone bought in and the performances on the field, everyone stepped up. It was fun."

So could a similar, vocal presence have helped the Phillies a year earlier?

"No - it just wasn't our year, it was the Cardinals' year," Pence said. "We were really good that year, but who's to say, you can't say that a speech is why we went and did what we did. You can't say a speech would have changed the Phillies-Cardinals outcome."