PHILADELPHIA -- Ryan Zimmerman was robbed in the first inning. He hit the ball too far and too hard for the Phillies to handle in his next two at-bats.

Baseball's hottest hitter, Zimmerman continued his remarkable stretch with the bat and accounted for three RBIs in the Washington Nationals' 6-2 win over the Phillies on Saturday night.

Zimmerman leads the majors in multiple categories including average (.435), OPS (1.382) and RBIs (34). He improved all of those numbers by going 2-for-4 with a two-run home run and an RBI double. The homer was his 13th, moving him into a tie with New York Yankees right fielder Aaron Judge for the major league lead.

Zimmerman extended his hitting streak to 13 games and the way he is hitting has manager Dusty Baker making comparisons to a great hitter he managed in San Francisco from 1993 to 2002.

"That's Bonds-like," Baker said. "He continues to stay on the ball, he's been hot for an extremely long period of time. This is as good a start as anyone I've ever seen."

Zimmerman homered in the fourth inning against Phillies starter Vince Velasquez (2-3), launching an 0-1 changeup into the left-field seats. He followed it up by drilling a line drive to right field in the sixth. Phillies outfielder Michael Saunders appeared to lose the ball in the lights, and it got over his head for an RBI double.

Three pitches later, Anthony Rendon broke the game open with a three-run homer to give Washington a 6-1 lead.

Both of Zimmerman's big hits came after he had extra bases taken away from him in the first inning by Phillies center fielder Odubel Herrera. Zimmerman hit a deep fly ball, but Herrera was able to track it down and make a leaping catch at the wall, possibly taking another homer away from the 13-year veteran.

Even with all the production through 29 games, Zimmerman downplayed his impressive start, saying he hasn't thought much about it.

"When you're in the middle of it, you're playing every day, you just want to keep doing your routine, keep doing your work and go out there every day and not think about it," he said.

It was the fourth straight win for the first-place Nationals, who were without Bryce Harper for a second consecutive game due to tightness in his groin. Harper is hitting .376 on the season, but his absence was not felt thanks to Zimmerman and Rendon, who has 17 RBIs in his last six games.

"It feels good to be able to get hits every night and continue to keep it rolling," Zimmerman said. "Tony has been swinging the bat well. This whole lineup is, I don't want to say competition, but we each push each other and continue to get hits so you can keep up with everyone else."

Meanwhile, it was the fifth straight loss for Philadelphia, marking the team's worst losing streak of the season.

The Phillies were unable to capitalize against Washington right-hander A.J. Cole (1-0), who was making his season debut. Cole worked around command issues throughout his start, and the Phillies were only able to get one run across in six innings despite having 10 baserunners (six hits and four walks).

The Phillies started the scoring in the second inning when Cameron Rupp grounded a single up the middle to plate Freddy Galvis. The damage could have been worse against Cole, but he got out of the first inning unscathed thanks to an unconventional double play.

With runners on the corners and one out, Maikel Franco struck out swinging and was subsequently called for batter's interference as he got in the way of catcher Matt Wieters with Herrera trying to steal second.

"When things aren't going your way, everything seems to happen," Phillies manager Pete Mackanin said. "It snowballs. It's not fun to lose five in a row."

Rupp hit a solo homer in the seventh, his third of the season, off Oliver Perez to make it 6-2.

Velasquez surrendered six runs and seven hits, but he was able to stay in the game and pitch seven innings. He also notched eight strikeouts on the night, his second-highest total of the season.

"Vinny pitched very well. He kept his pitch count down early then got into trouble a little bit later with the home runs," Mackanin said. "The middle of their lineup is just really good. They produce. They're really producing runs. You can't make mistakes to them."

NOTES: Nationals OF Bryce Harper missed his second straight game with groin tightness. Manager Dusty Baker said Harper, who tweaked his groin on Thursday, could return to the team's lineup for the series finale. ... Phillies OF Aaron Altherr was held out of the lineup after hurting his left wrist while making a diving catch on Friday. ... Nationals 1B Ryan Zimmerman hit his 13th homer of the season. It was his second in as many nights and his 10th in 16 games. Zimmerman is now tied for the major league lead in homers with New York Yankees OF Aaron Judge.