Rookie Jordan Walker's two-run homer highlighted St. Louis' four-run fourth inning.
Paul DeJong also clubbed a two-run homer and Nolan Arenado had a two-run double for the Cardinals, who have won nine of 11 and totaled 46 runs while going 6-1 since the All-Star break
The Cubs saw a two-game winning streak end as they dropped the opener of a four-game series
Matz (1-7), making his third start since re-entering the rotation, allowed only a fourth-inning run, three hits and one walk en route to his first win in 21 outings (13 starts) in 2023. He struck out six.
After allowing six runs, three earned, in 3 1/3 innings against St. Louis in London on June 25, Chicago's Marcus Stroman (10-7) again failed to complete four innings vs. the Cardinals
The right-hander was plagued by some poor defense behind him in England, and again on Thursday, when he yielded five runs, four earned. Stroman gave up seven hits and four walks while fanning four in 3 2/3 innings.
In the first, St. Louis star Paul Goldschmidt (two hits, two runs) reached on an infield chopper, then went to third when Patrick Wisdom whiffed on Arenado's two-out grounder, the first of the third baseman's two errors. Ex-Cub Willson Contreras followed with an RBI double.
Stroman allowed a bloop double to right by Tyler O'Neill in the fourth, then served up Walker's ninth homer -- on an 0-2 count.
One out later, Lars Nootbar singled and stole second, and Wisdom couldn't make a throw following a sliding grab on Goldschmidt's infield single. After Nolan Gorman struck out, Arenado found the right field gap to score two for a 5-0 Cardinals lead
Chicago got on the board in the bottom of that frame. Seiya Suzuki's leadoff popup to short right field was lost in the lights, resulting in a double. He scored on Yan Gomes' two-out hit to right that Walker played into the catcher's first of two triples.
After Walker singled with one out in the fifth, DeJong cleared the right field wall against Michael Rucker for his 13th homer.
Gomes (three hits) tripled and scored on Christopher Morel's groundout in the seventh.
--Field Level Media