Chris Capuano struck out nine while combining with two relievers on a four-hitter, James Loney drove in two runs with a bases-loaded single and the Los Angeles Dodgers completed a three-game sweep of the Washington Nationals with a 2-0 victory on Sunday.

Capuano (3-0) allowed three hits and two walks in 6 2-3 innings, helping send the Nationals to their fourth straight loss after they entered the series with an NL-best 14-5 record.

Kenley Jansen followed Josh Lindblom out of the bullpen and pitched a hitless ninth for his second save in three chances after starting out with six straight balls and getting a visit from pitching coach Rick Honeycutt. Jansen then struck out his next two batters and fanned Jesus Flores with runners at first and second to end it.

Dodgers manager Don Mattingly met with closer Javy Guerra before the game after the right-hander allowed five runs and nine hits over two innings in his last three appearances. Mattingly told reporters that he would keep Guerra in that role instead of replacing him with Jansen.

Lefty Gio Gonzalez (2-1) allowed two runs, three hits and five walks through six innings, and struck out seven. He'd gone 6-0 in his previous eight starts since last Sept. 12 — the Nationals haven't scored more than two runs in any of his five starts while he's been in the game.

Gonzalez, who issued only four walks over his previous three starts combined, matched zeros with Capuano through five innings before walking Matt Kemp, Andre Ethier and Juan Uribe in succession with one out in the sixth. Loney then lined a 1-2 pitch the other way to left-center, ending a scoreless streak of 25 innings by Gonzalez — the longest by a Nationals pitcher since the franchise left Montreal.

Tyler Moore, the Nationals' minor league player of the year in 2010, made his major league debut in left field and was 1 for 4 after getting promoted from Triple-A Syracuse.

On Saturday night, top prospect Bryce Harper made his big league debut for the Nats in left field and went 1 for 3 with a double and sacrifice fly. Harper shifted to center field on Sunday after Jayson Werth was a late scratch for an undisclosed reason.

Gonzalez was struck on his pitching arm by a line drive off Kemp's bat leading off the fourth, but recovered in time to throw him out. He then walked Ethier on four pitches before Harper made his first defensive gem in the big leagues — robbing Uribe of extra bases with a running catch and slamming into the padded fence before falling to the ground.

Harper went 1 for 3.

NOTES: Moore singled in the fifth for his first big league hit. A roster spot opened up for him when the Nationals placed INF Mark DeRosa on the 15-day disabled list because of an oblique strain on his left side. ... Only two players in the Nats' lineup entered Sunday with more than three RBIs — cleanup hitter Adam LaRoche (17) and leadoff man Ian Desmond (seven). ... Gonzalez has yet to allow a home run in 29 2-3 innings after giving up 17 last year. ... Capuano is 6 2-3 innings away from 1,000 in his nine-year career. ... Jansen has allowed no earned runs in 8 1-3 career innings against Washington.