SAN FRANCISCO -- Giants manager Bruce Bochy expected good things from Tim Hudson. He's getting even better results than he anticipated.
"I've always admired him from the other side, how well he competes," Bochy said. "I felt we were getting a front-line pitcher who will give us a chance to win on a consistent basis. He's done all we've expected and even more."
Michael Morse got three hits and scored twice for the Giants, who had a five-game winning streak before Washington came to town. The Nationals have lost just twice in 10 games.
"It's not much fun playing the fourth game of a series trying not to get swept," Bochy said. "The guys did a good job of forgetting the first three games and went out and played well."
Hudson (7-2) allowed one unearned run and six hits. He walked two, struck out five and improved to 3-0 in his last five starts, which includes a suspended game. The Giants are 7-0 in games Hudson has started at home.
"We played good defense to keep me out of some jams," Hudson said.
Blake Treinen (0-3) remained winless at the major league level despite a 2.08 ERA. He gave up two runs and five hits in five innings.
"I'm confident I can compete at this level," Treinen said. "But I still need to improve, especially the command of my fastball."
Pinch-hitter Hector Sanchez had a two-run single for the Giants.
Hudson allowed two or fewer runs for the 10th time in 13 starts. He beat the Nationals for the 17th time, the most of any active player, in 30 starts.
"I just try to go out there and give us a chance to win," Hudson said. "It doesn't matter than we lost three in a row or won three in a row. I feel like I put forth the same effort every time. When you have lost three straight to the same team there's more urgency behind it."
Treinen, who replaced the injured Gio Gonzalez in the starting rotation, has pitched against tough competition. The four starters he's faced have combined for 14 opening day starts.
"He's done well and is working hard at every aspect of the game," Nationals' manager Matt Williams said. "He has that power slider, which is his go-to pitch. Working on the development of his other pitches is what is important."
The Nationals got a run back in the fourth when Jayson Werth singled, took second on a passed ball and scored on LaRoche's single.
Giants INF Marco Scutaro (back) was scheduled to start swinging a bat to see how he's progressing. `'He's looking forward to getting his rehab going," Bochy said. `'He wants to start doing baseball activities." ... Gonzalez was scheduled to make one last rehab start Thursday before rejoining the team. ... Washington RHP Jordan Zimmermann (5-2, 3.17) starts at St. Louis on Friday night. He is 0-4 in seven starts against the Cardinals. ... RHP Tim Lincecum (5-4, 4.97) will start for the Giants when the Colorado Rockies come to town for a three-game series beginning Friday.