(AP Photo/Jeff Roberson)
In a span of four pitches, Lohse (0-1) issued his first walk all year, then allowed Neil Walker's two-run double and Andrew McCutchen's second homer to put Pittsburgh ahead 4-1.
Joel Hanrahan got four outs to preserve a one-run lead for his third save in three chances for the Pirates, who are 3-1 on the road to start the year after going a major league-worst 17-64 away from home last season.
The Cardinals were 1 for 9 with runners in scoring position and 2 for 16 with men on base against Morton (1-0) and four relievers. Albert Pujols was 0 for 3 with a walk and is 2 for 16 with a homer and one RBI thus far.
Morton was 2-12 with a 7.57 ERA last year and 0-8 with a 9.00 ERA on the road. St. Louis starters were batting a collective .540 against the right-hander entering the game but totaled a run on three hits in six innings.
Morton also won in April for the first time after entering 0-5 with a 12.57 ERA in five career starts and enjoyed his first success in St. Louis. The road victory was his first since he shut out the Cubs at Wrigley Field to end the 2009 season.
The Cardinals got two hits and a walk to start the eighth against Evan Meek, including Lance Berkman's RBI single. Allen Craig's run-scoring groundout cut the deficit to one and Craig stole second, but Mike Crotta struck out David Freese and Hanrahan fanned Yadier Molina.
Lohse had a 1.88 ERA in spring training, showing he'd recovered from a forearm injury that dogged him the last season and a half, and limited the Pirates to two hits through the first five innings. Lohse, who was 4-8 with a 6.55 ERA last year, allowed four runs and six hits.
Cardinals pitchers had worked 14 consecutive scoreless innings before the sixth.
Berkman walked on a full count to open the second, went to third on Craig's perfectly placed hit-and-run single and scored on a double-play ball to put the Cardinals ahead.
Morton prevailed in a 10-pitch at-bat against Molina in the fourth, inducing a groundout with runners on second and third. Molina entered 4 for 5 against Morton.
* Kyle McClellan, the Cardinals' setup man, makes his first career start today after 202 relief appearances. McClellan was 4-0 with a 0.78 ERA in spring training.
* St. Louis pitcher Jaime Garcia and Cubs shorstop Starlin Castro were co-NL players of the week.
* Berkman's bat sailed into the stands behind home plate and it struck a youngster, who left holding a towel over his right eye.
* The Pirates were 1-5 in St. Louis last season.