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Anticipation was the toughest part of the game-day experience for Michael Wacha.

Before making his major league debut, the St. Louis Cardinals pitcher had to wait out an hour-long rain delay.

"I think the worst part was just sitting around all day," Wacha said. "Once I threw the first pitch for a strike I really calmed down and was able to execute my pitches pretty well."

The end was pretty rocky for a bullpen minus closer Edward Mujica, victimized for a three-run ninth that spoiled Wacha's almost spotless showing in a soggy 4-2 loss to the Kansas City Royals on Thursday night.

"I'll never forget this day, that's for sure," Wacha said. "Even if I wasn't pitching. I'm not used to playing too many games at 2:30 in the morning."

Manager Mike Matheny said it was a shame Wacha's outing "was kind of going to fall on the back page."

Hall of Famer George Brett's debut as interim batting coach was a success and the Royals avoided a four-game sweep despite totaling just four hits in a marathon delayed an hour before the first pitch and another 4 hours, 32 minutes not long after the Royals took the lead with the bases loaded and none out in the top of the ninth.

It took 12 minutes to get the last six outs of a game that would have been a snappy 2 hours, 27 minutes without the rain.

From a near capacity crowd of 43,916, a couple hundred fans at most were around when the game scheduled to start at 7:15 p.m. CDT ended at 3:14 a.m.

Umpire crew chief Joe West opted for patience and declined to invoke a rule clause in the final season meeting between teams that would have wiped out the top of the ninth and declared the Cardinals 2-1 winners. Matheny and general manager John Mozeliak both lobbied on the field while crews got the field ready.

Matheny said the Cardinals had been in "constant contact with the league, and there's no real protest to file." He judged the playing conditions "bad."

"This comes down to one of my guys getting hurt, it's a big deal," the manager said.

The lengthy delay created a bit of a hardship for that crew, set to work a Cubs day game on Friday.

"We worry about that game when we get to that one," West said to a pool reporter. "We had to worry about this game tonight."

The Royals traveled to Texas to start a weekend series Friday night and the Cardinals begin a three-game series at home against the Giants.

"They've got to travel to Texas, we get to go home and go to bed," Matheny said.

Matheny paid a hefty price for giving Mujica a day off after earning four saves in four days. Jeff Francoeur homered on the second pitch from Mitchell Boggs, a curious choice to get the ball in the ninth given season-long woes that left him with a double-digit ERA and included a stint in the minors.

Boggs (0-3) faced two batters, retired neither and was loudly booed by a near-sellout crowd forced into a second rain delay. He was demoted May 3 after a 12.66 ERA and 12 walks in 10 2-3 innings. He has allowed a run in three of four appearances since returning on May 19, and none of the first three outings came with the game on the line.

Matheny said after the game that set-up man Trevor Rosenthal also had been unavailable because of a heavy workload.

"He's been up five days in a row," Matheny said. "He hasn't been in all five but he was ready to go. We've got to take care of you. You hate to sacrifice anything to do it, we needed the other guys to come in and pick up the slack."

Eric Hosmer, who had one RBI the previous 10 games, bounced a bases-loaded double over a drawn-in infield off Victor Marte.

The 21-year-old Wacha, who allowed a run on two hits in seven innings, was the third rookie to debut as a starter for the Cardinals and came close to matching John Gast and Tyler Lyons as first-game winners. Wacha retired the first 13 batters and set down the side in order every inning except the fifth, when Lorenzo Cain doubled with one out and scored on Elliott Johnson's single.

Wacha made the Cardinals' fastest jump from draft day to the majors in 25 years after getting picked in the first round last June.

Louis Coleman (1-0) allowed a walk in 1 1-3 innings and Greg Holland finished for his eighth save in 10 chances and first since May 1. Holland's blown save on May 6 against the White Sox was his only other chance this month.

Francoeur had been batting .156 in May and didn't start for the second straight game, entering in a double switch in the seventh. He ended the Royals' 59-inning slump without a homer with his second of the season and first since April 10.

Allen Craig and David Freese had two-out RBI singles in the first off Jeremy Guthrie to give the Cardinals the lead. They left the bases loaded in the second, wasting a single by Wacha in his first career at-bat, and stranded two in the fourth.

Wacha had a chance to score from second on Carlos Beltran's hit, but the Cardinals didn't risk a play at the plate with the bases loaded, one out and the heart of the order coming up. Matt Holliday grounded into a force play at the plate and Craig grounded out to end the inning.

NOTES: Wacha is the eighth rookie pitcher to suit up for St. Louis this year and seventh to play. Reliever Michael Blazek was optioned to the minors earlier in the day without appearing in a game. ... Shelby Miller (5-3, 2.02) opposes the Giants' Matt Cain (4-2, 5.00) in the opener of a three-game series Friday. The Royals begin a three-game set at Texas with Wade Davis (3-4, 5.71) opposing Derek Holland (4-2, 2.97). ... Cardinals reliever Randy Choate was the winner Wednesday for his first decision since July 24, 2011, a span of 103 appearances. It's the third-longest streak in major league history.