ST. LOUIS -- Michael Wacha has had plenty of practice when it comes to pitching in rain-delayed games the last two years.

"You have a sense of what to expect and how to stay mentally ready," he said. "Today wasn't the first time I've been through it, so I have an understanding of what goes on."

The St. Louis Cardinals starter pitched 6 1/3 solid innings Tuesday before being forced out by a second rain delay, leading his team to a 3-2 win over the Minnesota Twins that completed a perfect 4-0 homestand at soggy Busch Stadium.

Wacha allowed three hits and two runs, walking one and striking out five, as he improved to 9-2 to become the third National League pitcher to reach nine wins. Pittsburgh's Gerrit Cole has 10 and the New York Mets' Bartolo Colon owns nine.

After allowing a two-out RBI double to third baseman Trevor Plouffe in the top of the first, Wacha waited out a 45-minute delay during St. Louis' half of the first. He retired 15 of the next 16 batters he faced after the delay, with his stuff getting progressively crisper and sharper.

"I thought he had swing-and-miss stuff," Cardinals manager Mike Matheny said, "and I thought he got better as the game went along. It's always tough to see what happens when he comes back out, but he's had quite a few of those games."

Wacha endured six weather delays last year, totaling 6 1/2 hours. Three of his last four starts have been affected by rain delays, including one of nearly 2 1/2 hours in a 5-1 loss May 30 to the Los Angeles Dodgers.

After his departure in the seventh, the St. Louis bullpen held on to the lead despite an RBI double by catcher Kurt Suzuki on the second pitch from reliever Seth Maness after a 47-minute stoppage.

Matt Belisle and Randy Choate tag-teamed their way through the eighth and Kevin Siegrist -- closer Trevor Rosenthal was unavailable for the second straight day with a knot in his right biceps -- induced a game-ending flyout from pinch-hitter Eduardo Escobar with men at first and second for his third save.

Minnesota (34-30) came within inches of forcing extra innings, but shortstop Eduardo Nunez's one-out drive off Siegrist slammed off the wall in left center for a double.

"It's a tough loss because we had our chances," Twins manager Paul Molitor said. "We couldn't get the big hit when we needed it. St. Louis has a knack for finding a way to win these games."

Kyle Gibson (4-5) took the loss, yielding six hits and three runs in six innings with two walks and four strikeouts. His big mistake came when he missed over the plate's middle in the third to first baseman Mark Reynolds, who cashed it in for a two-out, two-run single that snapped a 1-1 tie.

The Cardinals' first run came in the second when left fielder Randal Grichuk lofted a one-out sacrifice fly to left, barely scoring catcher Yadier Molina ahead of Shane Robinson's accurate throw home.

St. Louis (43-21) upped its home record to 26-7 hours after a New York Times story revealed the franchise is under investigation by the FBI and Justice Department for hacking personnel files of the Houston Astros.

"I think we've seen all the information," Matheny said, "and I think the guys understand that it has nothing to do with them in the clubhouse. Our job is to stay focused on what we can do instead."

NOTES: St. Louis RHP Lance Lynn (right forearm strain) played catch Tuesday morning for the first time since going on the 15-day DL Friday. Lynn plans to join the team on its road trip this weekend in Philadelphia. ... Minnesota CF Byron Buxton became the fourth player in franchise history to triple for his first MLB hit, the last being Jorge Polanco on June 27, 2014, in Texas. ... The Twins signed LHP Alex Robinson, their fifth-round pick out of Maryland. Robinson is the first Minnesota draftee to sign.