ST. LOUIS -- If Travis Shaw didn't seem terribly enthused about homering and knocking in the go-ahead run with an eighth inning single Tuesday night, it's perfectly understandable.

Watching your daughter go through open heart surgery does have a way of putting things in perspective.

Shaw's 11th and 12th RBI of the season against the St. Louis Cardinals enabled the Milwaukee Brewers to salvage a split of a day-night doubleheader at Busch Stadium with an 8-5 verdict in the nightcap.

Jose Martinez homered twice and drove in three runs in the opener as St. Louis blanked Milwaukee 6-0, winning its fourth straight game.

That streak was snapped in the nightcap. Shaw played a significant part in that, putting the Brewers (34-32) ahead in the fourth by following up Jesus Aguilar's solo homer with one of his own for a 3-2 edge.

In the eighth, Shaw laced a 3-2 fastball from Trevor Rosenthal (1-3) up the middle to score Domingo Santana from second and snap a 5-5 tie.

"My mind is still elsewhere," Shaw admitted. "It's nice to contribute and help this team, but there are more important things besides baseball. I've been thinking about her a lot."

Shaw missed the team's weekend series in Arizona. Despite his worries about his daughter, Shaw is hitting at an All-Star level, leading Milwaukee in RBI with 44 and tied for fifth in the National League with 17 doubles.

It's safe to say that if general manager David Stearns hadn't acquired Shaw from Boston in the offseason as a part of a package for pitcher Tyler Thornburg, the Brewers wouldn't be sitting atop the National League Central.

"It's nice to have him back in the lineup," said center fielder Keon Broxton, who homered and drove in three runs. "He deserved to have this happen tonight."

Milwaukee blew a 5-2 lead before stringing together the winning rally against Rosenthal, who issued consecutive walks to Santana and Aguilar before Shaw and Hernan Perez singled.

Closer Seung Hwan Oh relieved Rosenthal with his team losing and promptly allowed an RBI single to Manny Pina. Broxton finished the rally with a sacrifice fly to left fielder Jedd Gyorko, playing the outfield for the first time in the majors.

"Not throwing strikes was the big thing," Rosenthal said.

Jared Hughes (2-1) picked up the win for the Brewers despite allowing a game-tying leadoff homer to Matt Carpenter in the bottom of the seventh, his 12th of the year. Corey Knebel got the last three outs for his ninth save in 12 chances.

Carpenter went 3-for-5 for the Cardinals (30-33). He doubled and scored in the first on Martinez's fielder's choice, then singled home Greg Garcia an inning later for a 2-0 lead.

Broxton's eighth homer pulled Milwaukee within 2-1 in the third. He knocked out St. Louis starter Marco Gonzales in the fourth, ripping a triple to left-center that scored Pina for a 4-2 advantage. Broxton scored on a fielder's choice grounder by Orlando Arcia to make it 5-2, beating Garcia's off-target throw from third.

Gonzales lasted 3 1/3 innings, allowing six hits and five runs with no walks and two strikeouts in his first big league game since 2015. He missed last year after undergoing Tommy John surgery.

The Cardinals pulled within 5-4 in the sixth. After Eric Fryer's bases-loaded double play ball scored Kolten Wong, pinch-hitter Dexter Fowler delivered an RBI single that knocked off Jimmy Nelson.

In 5 2/3 innings, Nelson yielded nine hits and four runs, walking two and whiffing four. He was in line for his first win in nine decisions against St. Louis prior to Carpenter's homer.

But the Brewers won anyway, thanks to a rally where they taxed Rosenthal and Oh for a whopping 44 pitches.

"Give all those guys credit," Milwaukee manager Craig Counsell said. "Those were some outstanding at-bats. It's not the biggest numbers we've had offensively this year, but we needed that."

NOTES: St. Louis finally got to make its first choice in the 2017 First-Year Amateur Draft Tuesday, popping CF Scott Hurst of Cal State-Fullerton with the 94th overall pick. The Cardinals lost their first round pick for signing Dexter Fowler in free agency and two other selections to Houston as part of their penalty for "Hackgate." ... St. Louis C Yadier Molina (lower back stiffness) returned to the lineup for Game 1 of the doubleheader and went 1-for-4. He rested in Game 2, with Eric Fryer getting the call. ... Milwaukee placed RHP Brandon Woodruff (hamstring), who was scratched from his MLB debut in Game 1, on the 10-day DL and recalled RHP Paolo Espino from Triple-A Colorado Springs.