BALTIMORE—In the first half of the season, Matt Harvey had baseball’s worst ERA, 7.70, to go along with a 3-10 record. It’s been a far different story in the second half.

Harvey has started twice, pitched 12 shutout innings and allowed just four hits. On Saturday night, he retired 18 of the 19 batters he faced, allowing only Trea Turner’s fourth-inning double as the Orioles defeated the Washington Nationals, 5-3, before an announced crowd of 30,898 at Oriole Park, the largest of the season.

The fans came for Jim Palmer Bobblehead night, and the greatest pitcher in Orioles history obliged the fans by waving from the TV booth after the fourth inning.

Nationals-Orioles games feature fans of both teams, and Washington fans expected Max Scherzer to pitch. About two hours before game time, Nationals manager Dave Martinez said Scherzer, who’s been mentioned in trade talks, was being scratched because of a biceps tendinitis.

Jon Lester (3-5), who was supposed to start on Sunday, was moved up a day. He allowed home runs to Trey Mancini, his 17^th and first since the Home Run Derby, in the first ,and Ryan Mountcastle, his 16^th, in fourth before tiring in the sixth.

Lester was pulled after Cedric Mullins led off with a double in the sixth. Austin Voth allowed a double by Austin Hays that scored Mullins.

The Orioles (33-64) loaded the bases and scored on a Pedro Severino single and a sacrifice fly by Maikel Franco to right for a 5-0 lead.

Harvey (5-10), who suddenly might be a trade chip in advance of Friday’s trade deadline, struck out four and walked none. It was only his second start without a walk this season.

“Really feeling good with all the pitches,” Harvey said. “Especially the curveball. I haven’t thrown that a whole lot in the past, being able to get that over for a strike and also be able to feel confident with it to both righties and lefties, get ahead in the count. It’s been something we’ve been working on for a while now. Tonight was obviously the first night I felt good with it throughout the outing.”

Harvey wouldn’t speculate on the trade deadline.

“Obviously, everybody knows when it is, and it’s there,” Harvey said. “My job is to go out and prepare for each start and see what happens. I haven’t put up very good numbers other than the previous two [starts]. To really be a target or whatnot.

“But at the end of the day, those decisions aren’t mine, so I can’t really worry about them. My job is to go out and win ballgames for the Orioles and, luckily, I’ve been able to do that the last two, and I’m going to continue to do that from here on out.”

Adam Plutko replaced Harvey for the seventh and gave up Juan Soto’s 17^th home run, an opposite-field shot to left.

Harvey threw 83 pitches through six. In his 20 appearances, he’s averaged 80 pitches. Hyde considered sending him out for the seventh.

“I would have liked to,” Hyde said. “I talked to Matt after the sixth, and told him it was time to go with someone else.”

In the eighth, Josh Harrison led off with a double, and Tanner Scott replaced Plutko and hit his first two batters, Carter Kieboom and Tres Barrera, to load the bases.

Scott got Victor Robles on a called third strike and Alcides Escobar was out swinging before Trea Turner dumped a two-run single to short right field. Soto popped out to Severino, and the Orioles led, 5-3.

“He made the pitch of the game there to Soto,” Hyde said. “The hit to Trea was disappointing as well as hitting two guys on the foot … Soto’s a top-five player in this game, and one of the dangerous and hottest and to be able to pop him up there in a big spot shows a lot about Tanner. He’s not going to be perfect. We all know he’s got electric stuff … He got out of the inning with the lead and made some big pitches when he needed to.”

Dillon Tate pitched a scoreless ninth for his second save.

The Orioles have won five of their eight games after the All-Star break. Washington (45-52), might decide to begin playing for 2022 and beyond.

Notes: The Orioles signed three additional draft choices — infielder Collin Burns, their sixth-round pick, catcher Connor Pavolony, chosen in the seventh round, and 20^th-round pick outfielder Trendon Craig. They’ve signed 20 of 21 draft picks. The only unsigned draft pick is right-handed pitcher Daniel Lloyd, their 14^th -rounder. … John Means (4-3, 2.72 ERA) will face Paolo Espino (2-2, 3.00) on Sunday.  … The crowd was the largest since April 7, 2019. “The guys in the dugout were talking about it,” Hyde said. “It’s a noticeable difference. The energy, players were feeding off it. We should have Jim Palmer Bobblehead night more often.”

Minor league update: Dean Kremer (0-4) allowed three runs on seven hits in 4 2/3 innings as Triple-A Norfolk lost to Gwinnett, 5-2. It was the Tides’ fourth straight loss.

Kremer has lost 11 decisions, seven with the Orioles and four with Norfolk, without a win. He struck out three and didn’t walk a batter.

Adley Rutschman hit a game-tying two-run home run in the ninth, his 15^th of the season. Centerfielder Zach Watson hit a game-winning single as Double-A Bowie scored three runs in the ninth to beat Hartford, 6-5. Watson also hit his first home run since coming up from Aberdeen.

Grayson Rodriguez allowed four runs on three hits in 1 2/3 innings. He struck out five and walked two.

Catcher Ramon Rodriguez had three hits and drove in four runs as High-A Aberdeen beat Hudson Valley, 8-5.

Drew Rom (8-0) allowed one run on three hits in five innings. Shortstop Gunnar Henderson had two hits and raised his average to .235.

Leftfielder Lamar Sparks had three hits and first baseman TT Bowens drove in two runs as Low-A Delmarva beat Lynchburg, 7-3.