Jack Flaherty pitched five effective innings for St. Louis in his first big league action since June, but the NL Central-leading Cardinals had their four-game winning streak stopped by Joey Meneses and the Washington Nationals 6-0 Monday.
Meneses got three hits and fellow rookie C.J. Abrams had four to back five shutout innings from Anibal Sanchez (2-5). Washington, which has the worst record in the majors, has won three in a row.
Flaherty (0-1) returned from the injured list after being sidelined by a right shoulder issue. In his first start since June 26, he allowed one run on six hits and a walk. He struck out six and hit a batter while throwing 91 pitches.
Anibal Sanchez gave up just two hits. It was his first start at Busch Stadium since he threw 7 2/3 no-hit innings in the opener of the 2019 NL Championship Series.
St. Louis managed just three singles against three pitchers. Mason Thompson allowed one hit in three innings for his first big league save.
The Cardinals have won seven of their last nine games and 23 of 31.
The Cardinals activated Flaherty from the 60-Day injured list and optioned RHP Dakota Hudson to Triple-A Memphis.
Cardinals LHP Jose Quintana (4-6, 3.47) will be making his third start of the season against the Nationals and his first as a member of the Cardinals. The Nationals are one of five teams that he has no career wins against.