Zimmermann turned in a dominant effort in his last outing and will pitch Sunday when the visiting Nationals complete a three-game set against the San Diego Padres.
Washington (31-29) was one out from establishing its longest win streak of the season at five Saturday, but closer Rafael Soriano allowed a tying home run in the ninth inning by Yonder Alonso. Cameron Maybin's RBI single in the 11th inning gave San Diego (28-34) a 4-3 victory.
"We're grinding, man," Maybin said. "It was bigger to get a win tonight. We've been scuffling but we've been battling every night. For me it was huge because we have a chance to win the series tomorrow.''
Winning the series could be difficult for the Padres. They are last in the majors in runs (195), batting average (.220) and on-base percentage (.280) as they face Zimmermann (4-2, 3.59 ERA).
Zimmermann was brilliant Tuesday, yielding five hits in a 7-0 rout of Philadelphia. He was happy to turn the calendar after going 1-1 with a 5.96 ERA in his last four starts of May.
"May was a pretty rough month for me, and hopefully June has better things to come," Zimmermann said.
Zimmermann is 1-2 with a 2.35 ERA in six career starts against the Padres, allowing three runs over six innings April 24 in a 4-3, 12-inning loss. Chase Headley is 3 for 16 against him and Will Venable is 1 for 15.
The right-hander is also 6 for 18 at the plate to rank as one of baseball's hitting pitchers.
Washington is no doubt more anxious to see if Rendon will be playing Sunday. Rendon, who leads the Nationals with 34 RBIs, left Friday's 6-0 victory with a sore right hand and sat out Saturday.
"We got a quick turnaround tomorrow so we'll have to see how it is," manager Matt Williams said. "The good news is, there was no fracture.
"It's better than last night, not as much swelling today as there was yesterday, but it's still sore. Probably more sore today than it was last night with adrenaline and being hot. So we'll see. He could be in there (Sunday) depending on how he feels."
The Padres don't figure to pose much of a threat at the plate based on how they have fared, which has been evident when Eric Stults (2-6, 5.03) is on the mound. Stults' 2.73 run support average is one of baseball's lowest marks.
Stults has posted a 6.48 ERA over his last three outings, yielding four runs in six innings last Sunday in a 4-1 defeat to the Chicago White Sox.
The left-hander opposed Zimmermann on April 24 and gave up two runs over 5 1-3 innings. Stults won his other career outing against the Nationals by yielding one run over eight innings in a 2-1 victory May 18, 2013, as Zimmermann went the distance in defeat.
The Padres are scuffling without Jedd Gyorko, who has a team-high 24 RBIs. Seth Smith is second with 21, but just one in his last 10 games.