"I was excited. Of course, then the (television) announcer said, 'have fun following this one, Justin,' "Masterson said with a big smile. "Rolling through my mind was I wanted to throw a perfect game or maybe back-to-back no-hitters, but that was taken away in the first inning."
David DeJesus doubled with two outs in the first, but Masterson (1-0) allowed just two more hits before leaving with a 2-0 lead with one out in the seventh inning.
Just one night earlier, Lester beat the Royals 7-0 with the first no-hitter of the season.
After Tuesday's game, Masterson, a 6-foot-6 right-hander with a deceptive whip-like motion, was optioned to Triple-A Pawtucket to make room for former AL Cy Young winner Bartolo Colon, who will make his first start of the year in his 12th major league season Wednesday.
Masterson will be a tough act to follow, just as Lester was.
"I don't really mind" going to the minors, said Masterson, who was brought up Tuesday from Double-A Portland. "It's kind of cool that I got to pitch Tuesday and he's back to Wednesday."
He allowed one run on three hits with five strikeouts and three walks in his second major league start. Manager Terry Francona expects him to make many more, perhaps late in the season, perhaps next season.
"You can make some mistakes by rushing guys" to the majors, he said. "He needs to go pitch and enjoy his development and enjoy getting better because he's going to help us."
"We ended up with the bases loaded and they bring in the big boy," Kansas City manager Trey Hillman said. "Billy was right on the fastballs, but he threw a nasty slider. That's tough duty."
The Red Sox needed Masterson after a rainout Friday night forced them to play a doubleheader on Saturday. In his only other start, he allowed one run and two hits in six innings in a 7-5 win over the Los Angeles Angels on April 24, also at Fenway Park.
Boston won its fifth straight game, while Kansas City lost only the third of its last nine.
"I wouldn't say it was more frustrating" than the no-hitter, Hillman said. "We are a little bit out of sync with runners in scoring position."
They wasted an excellent chance in the eighth when they loaded the bases with two outs against Hideki Okajima on a ground-rule double by DeJesus and walks to Alex Gordon and Mark Teahen. Papelbon then fanned Butler and pumped his fist several times as he walked from the mound.
Kansas City also got a strong performance from its starter.
Gil Meche (3-6) allowed two runs on five hits with seven strikeouts in seven innings and retired 16 of his last 18 batters after Boston took a 2-0 lead in the second.
"In my last four starts my stuff is coming back," he said.
Meche retired the leadoff batter in the second before four of the next five runners reached base.
The Red Sox loaded the bases on singles by Kevin Youkilis and J.D. Drew and a walk to Jason Varitek. Julio Lugo sent home the first run with a sacrifice fly and Coco Crisp drove in the second with a double.
Then Meche set down the next 10 batters.
Kansas City scored in the seventh, which started with Masterson's leadoff walk to Teahen. Masterson then threw out Butler on a grounder to the mound as Teahen took second. Masterson left to loud applause after throwing 91 pitches and Javier Lopez struck out Ross Gload.
Then right-hander Delcarmen came in and allowed the RBI single to righty Buck. Delcarmen ended the threat by striking out Alberto Callaspo, who struck out to end Lester's no-hitter.
- Colon signed a minor league contract in spring training.
- Gordon reached base on all four of his at bats with two doubles, a single and a walk.
- Manny Ramirez struck out three times and is stuck at 498 homers since hitting his last on May 12.
- The Red Sox sent RHP Chris Smith to Triple-A Pawtucket to make room on the roster for Masterson.
- RHP Julian Tavarez accepted an assignment to Pawtucket eight days after being designated for assignment by Boston.
- Red Sox bench coach Brad Mills coached third base while DeMarlo Hale tended to his wife, who is having medical tests in Orlando.