Mike Piazza hit a pinch-hit two-out home run off closer Chad Cordero, who blew his third save of the season, to secure the weekend series sweep for San Diego. The first-place Padres have won all six games in the nation's capital since the Nationals franchise relocated to Washington D.C.
Washington's bullpen entered the game with a scoreless-innings streak going on 17 frames, but was pressed into action early because starter John Patterson left the game with a right forearm strain after one inning. The bullpen was already tired, having worked 7 2/3 innings the previous two days.
"I understand how tired the bullpen is," catcher Brian Schneider said. "The bullpen needs a break."
Six relievers combined to pitch the final eight innings, giving up nine runs on 15 hits. Cordero came on in the eighth and gave up a run, narrowing his team's lead to one run. But Schneider's two-run shot in the bottom of the inning padded Washington's cushion.
The Padres hit two doubles to lead off the ninth, both to deep center field. Center fielder Alex Escobar got a bad break on the first double, which fell over his head, and Escobar couldn't quite catch up to the second one.
"They were pretty well hit," he said. "Late in the afternoon, the sun gets right in the middle and it's tough to pick up the ball."
After those doubles, Khalil Greene hit a game-tying two-run homer. Two outs later, Piazza stepped to the plate and didn't miss a fastball down and in.
"He has a lot of power in that spot, and I threw it to where he likes it," Cordero said. "And he hit it like 500 feet."
Cordero, who pitched two innings Thursday, gave up six hits Sunday -- all for extra bases. He threw a career-high 55 pitches in his 1 2/3 innings, suffering his fourth loss of the season.
"It's real tough," he said. "I just made mistakes and they made me pay for it."
For Patterson, it was the shortest start of his career. He threw 31 pitches, giving up one run on three hits. The first four Padres reached base against Patterson, but he escaped a bases-loaded, no-outs jam in the first. Robinson talked with him after that inning and decided it was best for Patterson to come out.
Patterson missed nearly two months earlier this season with the same injury. Sunday marked his fourth start back from the disabled list, and since returning, his arm has continued to bother him.
"It hasn't seemed to progress too much," he said. "It's been a rough year. It's been nothing like I expected."
Patterson received a cortisone shot after leaving the game and will get treatment before the team heads to Pittsburgh to start the second half of the season. He expects to play catch after the break and make his next scheduled start, which will be in Florida.
Sunday marked the third time the Nationals scored nine runs during the their 10-game homestand -- but they still lost two of those games. They finished the home stretch 5-5, dropping to 20-24 at home this season.
Escobar has a hit in each of his four games since returning from the disabled list Thursday, and he was a perfect 4-for-4 Sunday, including his first Major League home run since May 23, 2004, when he played with Cleveland. The four hits were a career best for Escobar.
Four of the eight Washington position players had at least two hits. Ryan Zimmerman laid down a bunt single in the first, extending his hitting streak to a career-high 12 games, and later hit an RBI double.
The Nationals finished the first half in last place in the National League East, 15 1/2 games behind the New York Mets. Last season at this point, Washington was 52-36 and leading the division by 2 1/2 games.
Michael Gluskin is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.