Clayton Kershaw (12-7) pitched three-hit ball over eight innings for the new-look Dodgers, hours after they acquired Gonzalez, Carl Crawford and Josh Beckett in a blockbuster trade with Boston.
Ethier and Mark Ellis also went deep for Los Angeles.
Ethier had his second straight four-hit game. He gave the Dodgers a 7-2 lead in the fifth with a leadoff homer against reliever Wade LeBlanc and added a bloop single to centre in the seventh for his 10th consecutive hit, tying a club mark set in 1919 by Ed Konetchy.
Marlins starter Josh Johnson (7-11) threw 89 pitches in three innings, giving up six runs and 10 hits. He retired only nine of the 20 batters he faced in his shortest outing this season. The two-time All-Star has lost his last four starts.
BRAVES 7, GIANTS 3
SAN FRANCISCO (AP) — Jason Heyward hit a three-run homer and Atlanta snapped San Francisco's five-game winning streak.
Michael Bourn had two hits and two RBIs for the Braves, who had lost six of seven but still lead the NL wild-card race. Reed Johnson and Martin Prado each drove in a run.
Atlanta left-hander Mike Minor (7-10) gave up three runs and four hits in 6 2-3 innings. He also doubled, walked and scored twice.
Minor was 1-4 with a 2.22 ERA in his previous seven starts.
Pinch-hitter Gregor Blanco had a two-run double for the NL West-leading Giants, who had won eight of 10.
Madison Bumgarner (14-8) allowed four runs and seven hits over 6 1-3 innings. He matched his season high with four walks and struck out five, losing for only the second time at home.
PHILLIES 4, NATIONALS 2
PHILADELPHIA (AP) — Roy Halladay outpitched Gio Gonzalez with seven solid innings and John Mayberry Jr. homered to lead Philadelphia to its third consecutive victory.
Halladay (8-7) allowed two runs and seven hits, struck out six and walked one. The right-hander, who missed 42 games with a strained muscle, is 4-1 with a 2.75 ERA in his last five starts.
Steve Lombardozzi drove in both runs for Washington, which lost its third straight. Gonzalez (16-7) gave up three runs and five hits in six innings.
After Antonio Bastardo struck out the side in the eighth, Jonathan Papelbon closed it out for his 29th save in 32 chances.
REDS 8, CARDINALS 2
CINCINNATI (AP) — Brandon Phillips hit his first home run in August, Mike Leake pitched effectively into the seventh inning and the Reds strengthened their hold on the top spot in the NL Central.
Phillips and Ryan Ludwick had three hits apiece and Jay Bruce added a two-run homer as Cincinnati regained a seven-game lead over second-place St. Louis, which rallied to win the series opener 8-5 on Friday night.
Leake (6-8) yielded at least one hit in every inning except one, but kept the Cardinals mostly at bay. Leake, who also had two hits, lasted 6 2-3 innings, allowing 10 hits and two runs.
St. Louis left-hander Jaime Garcia (3-5) gave up four runs and seven hits in six innings. He entered with a 7-1 record and a 3.12 ERA in nine career starts and two relief appearances against the Reds.
METS 3, ASTROS 1
NEW YORK (AP) — R.A. Dickey helped his own cause for his 16th victory, driving in a run with an infield single and pitching seven solid innings to help the Mets stop a six-game skid.
Justin Turner hit his first homer of the season and Jason Bay snapped an 0-for-14 slump with an RBI single in the eighth that ended a stretch of offensive futility for the Mets. New York went seven straight games without scoring more than two runs for the first time since September 1982.
Dickey (16-4) yielded just five singles in tying the NL's Gio Gonzalez and Johnny Cueto and the AL's Jered Weaver and David Price for the major league lead for wins.
Frank Francisco pitched a perfect ninth for his 21st save.
Houston starter Fernando Abad (0-1) gave up one run and four hits in four innings.
PIRATES 4, BREWERS 0
PITTSBURGH (AP) — Jeff Karstens pitched seven-plus innings before leaving with an injury and the Pirates snapped a four-game losing streak.
Karstens (5-3) gave up seven hits, did not walk a batter and struck out four for his first win in nine career starts against Milwaukee.
Karstens also had an RBI single and scored during Pittsburgh's four-run fifth inning, but left with an injured right groin after the first two Brewers singled in the eighth.
Pedro Alvarez had two hits for the Pirates, who are one game behind St. Louis for the second wild-card spot.
Shaun Marcum (5-4) did not allow an earned run in his first start since June 14 but took the loss due to two errors in the Pirates' fifth.
Aramis Ramirez had three hits for the Brewers, who had won four in a row.
ROCKIES 4, CUBS 3
CHICAGO (AP) — Carlos Gonzalez used his speed to beat out a potential double-play ball in the seventh inning and drive in the go-ahead run in the Rockies' victory.
Andrew Brown hit his first career homer and pinch-hitter Josh Rutledge had a two-run shot for Colorado, which has won six of seven. Carlos Torres (3-1) threw 2 1-3 scoreless innings as four Rockies relievers combined for five innings of one-hit ball.
Brett Jackson hit a two-run homer for Chicago, which has dropped five of six and seven of nine. Manuel Corpas (0-1) got the loss.
The Rockies grabbed the lead for good in the seventh. With runners on first and third and one out, Gonzalez hit a grounder to first baseman Anthony Rizzo and beat the return throw from shortstop Starlin Castro, allowing DJ LeMahieu to come home.
Rafael Betancourt worked the ninth for his 26th save in 31 chances.
PADRES 9, DIAMONDBACKS 3
PHOENIX (AP) — Yonder Alonso hit the last of San Diego's three solo homers and added a two-run single to lead the streaking Padres past Arizona.
Chase Headley and Carlos Quentin also homered for the Padres, who have won six in a row.
Clayton Richard (11-12) allowed three runs over eight innings, improving to 5-0 in seven career starts against Arizona.
Justin Upton celebrated his 25th birthday with his first career inside-the-park home run and Aaron Hill also connected for the slumping Diamondbacks. Arizona is 4-9 in its last 13 home games after winning eight straight at home in July.
Ian Kennedy (11-11) gave up six runs and four hits over 5 1-3 innings. He walked four and hit a batter with a pitch.