ST. LOUIS -- By the time he makes his next start, Mike Leake might not be a member of the Cincinnati Reds.

Regardless of whether he pitches for Cincinnati or for a contender, Leake will do so on perhaps the best run of his career.

Shutting down the St. Louis Cardinals on four hits over eight innings Tuesday night, Leake led the Reds to a 4-0 win at sweltering Busch Stadium.

In improving to 9-5, Leake won his fourth straight start and upped his record to 7-1 in his last eight decisions. Leake has allowed just two runs in his last 30 innings, giving up only 15 hits and four walks in that span.

"It's been a long six years," Leake said, referring to his big league career. "It's just a matter of learning a lot, and I feel like I've learned a lot in these last few starts."

In no way did Leake resemble the pitcher who was 4-7 with a 4.75 ERA in his career against St. Louis before Tuesday night. Working fast and hitting the corners, Leake didn't permit a hit until rookie right fielder Stephen Piscotty laced a single to right field with two outs in the fifth.

Leake walked one and fanned three in his 95-pitch outing, a performance which can do nothing but enhance his growing trade value for contenders that might be priced out of the Cole Hamels sweepstakes.

"I know there's a lot of teams out there that like him, but our plan is for him to pitch Sunday unless something happens," Cincinnati manager Bryan Price said. "That's an organizational decision, though."

The only offense Leake needed came off the bat of Joey Votto. The Reds first baseman broke up a scoreless tie in the top of the sixth inning with a three-run homer over the center field wall, his 19th of the year.

In his last 17 games, Votto is batting a scalding .484 (30-of-62). He has eight extra-base hits since the All-Star break and has reached base in 11 of his last 12 plate appearances.

"It's phenomenal," Price said of Votto. "It's not just the base hits, it's laying off the tough pitches and getting hits off tough pitchers. It's been a great run and I hope everyone appreciates that Joey is back."

Votto's homer was the only really bad pitch thrown by St. Louis left-hander Jaime Garcia (3-4), making his first start since suffering a groin injury June 24 in Miami. Garcia gave up three runs off four hits and two walks in six innings, fanning five.

Cardinals manager Mike Matheny pointed to a walk that second baseman Brandon Phillips drew just before Votto's blast as a turning point. Garcia had Phillips down 1-2, but couldn't put him away, just missing with a 3-2 slider down and in.

"I think that was probably a ball, but it was close," Matheny said. "You look back at the home run pitch, he made a lot of good pitches up to that point. Votto's swinging the bat well and he's not going to let a lot of mistakes go by."

Right fielder Jay Bruce capped the scoring with an RBI single in the ninth as Cincinnati (44-54) won for only the 19th time in 51 road games.

St. Louis (64-36) lost for just the 14th time in 51 home dates and saw its National League Central lead over Pittsburgh, an 8-7 winner in Minnesota, fall to 5 1/2 games.

NOTES: St. Louis optioned RHP Sam Tuivailala to Triple-A Memphis to make room for Tuesday night's starter, LHP Jaime Garcia. Tuivailala logged eight straight scoreless appearances for the Cardinals with seven strikeouts in eight innings. ... St. Louis C Yadier Molina (illness) was back in the lineup after leaving Monday night's game in the bottom of the fifth inning for a pinch-hitter, but CF Randal Grichuk (groin) didn't start for the second straight game. ... Cincinnati 1B Joey Votto entered Tuesday night's game with a .526 average since the All-Star break, the best in the major leagues.