CHICAGO (AP) -- Gio Gonzalez delivered another dominant performance, providing more evidence he is finally healthy again.
It looks as if the shoulder problem that sidelined him for a month bothered the left-hander about as much as the opposing hitters.
Gonzalez had his way with one of the weakest lineups in the majors in his third start back from the disabled list, outperforming Dallas Beeler in the righty's major league debut.
''Obviously coming (off) the DL and trying to work your way back is going to be a process,'' Gonzalez said. ''It's not going to happen overnight. It's good to see little by little using fastball and changeup at the same time. It's good to know when you need them they'll be there.''
Anthony Rendon had three hits, including a two-out double against Beeler in the sixth before scoring the game's first run on a wild pitch. He added an RBI triple off Justin Grimm and came home on a sacrifice fly by Adam LaRoche against Wesley Wright in a two-run eighth.
Denard Span chipped in with two hits and scored a run. He also made a leaping catch in front of the center-field wall after getting turned around on a drive by Justin Ruggiano in the fourth, and the Nationals snapped a three-game losing streak.
Gonzalez (5-4) had little trouble against a team that came in with the majors' second-worst batting average.
He struck out seven and walked two while improving 2-0 in three starts after missing a month because of inflammation in his pitching shoulder. He shut down Chicago after throwing six effective innings in a 3-0 win at Milwaukee on Monday.
Tyler Clippard worked the eighth and Rafael Soriano finished for his 19th save in 21 chances.
As for Beeler, he was about as good as Gonzalez. Called up from Triple-A Iowa as the 26th man, he pitched four-hit ball while allowing an unearned run in six innings.
''I was a lot calmer than what I thought I'd be,'' he said. ''I walked out there, took a deep breath, threw my warmup pitches, kind of looked around again, exhaled and I was like, 'All right, same game I've been playing for the last 20 years.'''
Beeler also singled in his first at-bat when he lined the first pitch he saw up the middle in the third, drawing big cheers from the crowd.
Neither team got an extra-base hit until Rendon doubled to left in the sixth. He moved up on a passed ball by John Baker before Ryan Zimmerman walked, and he scored the game's first run when Beeler bounced a changeup to LaRoche.
Otherwise, it was quite a debut for the rookie.
''He was commanding his pitches,'' Rendon said. ''Sinker and cutter and a pretty good curveball out there.''
NOTES: The Nationals remain optimistic that OF Bryce Harper will return from a torn ligament in his left thumb early in the week, if not Monday. The 2012 NL Rookie of the Year, who was injured sliding head first into third in a game against San Diego in April, has been rehabbing in the minors. ''He's progressing really well,'' manager Matt Williams said. ''I feel good at some point this coming week (he will return), Monday is a possibility.'' ... Washington recalled Game 2 starter Blake Treinen and reliever Xavier Cedeno from Triple-A Syracuse while optioning RHP Taylor Hill to the minor league club. ... Chicago OF Junior Lake was back in the lineup for Game 1 after sitting out Friday. He slid hard into a metal door in the outfield wall and left Thursday's game. ... The Cubs have their first scheduled Sunday off in 82 years because of the annual Pride Parade in Chicago. The last one was on June 19, 1932. Chicago played the Giants in New York on a Saturday and then visited Philadelphia on a Monday.