PITTSBURGH -- This can't be a good sign for National League hitters. Randy Johnson's back isn't hurting as much as before and his strikeout numbers keep going up.
Johnson, rounding into shape at age 43 following offseason back surgery, struck out 10 in 5 2/3 innings to win his second start in a row and pitch the Arizona Diamondbacks to a 5-2 victory over the Pittsburgh Pirates on Sunday.
Johnson (2-2), often resembling the dominating pitcher he was while winning five Cy Young Awards, was lifted after throwing 102 pitches -- regularly hitting 96 mph with his fastball. He gave up two runs and seven hits.
The Big Unit has struck out 19 in 11 2/3 innings over his last two starts, fanning the Pirates' No. 3-6 hitters a combined seven times. Jason Bay struck out three times and Ryan Doumit and Adam LaRoche twice each.
"It keeps getting better and better," Diamondbacks manager Bob Melvin said. "To me, this time, he was into the flow quicker than the past couple of times, (when) you saw the velocity climb. You saw it right away today and that's a good sign."
Johnson is resigned to not being 100 percent all season because of the back surgery, but he felt better than he did while striking out nine and limiting Colorado to one hit over six innings in a 3-0 victory Tuesday.
"Over the last couple of starts, the results have been good but I've been up and down physically," Johnson said. "Today, I actually felt good and battled. ... I'm coming back from surgery, and I'm not going to feel good all year -- until the season the over and I can rest the back."
By beating the Rockies and Pirates in his last two starts, Johnson has 282 career victories -- leaving him one away from tying Jim Kaat for 29th place on baseball's career list and 18 short of No. 300.
Pirates manager Jim Tracy talked afterward about how his team got Johnson out relatively early in the game, though it looked to be Johnson's pitch count and not the opposing hitters who forced him to leave.
"Every time he goes out there, the gas tank is improving," catcher Chris Snyder said. "His stuff's been there for three or four starts. The stamina gets better and better, so if he keeps that going it will be a good season for him."
Snyder made certain it was a good day for Johnson by getting a three-run double in the fourth that made it 5-1. Pirates starter Paul Maholm allowed rookie Mark Reynolds' single, Reynolds' fourth hit in two games, and walked two ahead of Snyder's double.
"I've left a small village out there lately, so it's good to finally come through one time and be productive," said Snyder, who was 1-for-17 before getting hits his first two times up.
After walking two to load the bases, Maholm (2-6, 5.82 ERA) tried to get ahead of Snyder with a first-pitch fastball, but made it much too hittable.
"My stuff is good enough to win," the left-handed Maholm said. "I've just need to be more aggressive throwing pitches in the zone. For some reason that's not happening right now, but I'm confident I'm going to turn it around."
A night after rallying from six runs down for a 9-8 victory that helped them out of their May hitting slump -- they averaged 2.9 runs in their first 16 games -- the Diamondbacks jumped on Maholm (2-6) with two runs in the third and three in the fourth.
"I think we took some big steps not only in coming back but having it carry over today," Johnson said. "We could look back later in the year and say yesterday (Saturday) was the game that kind of got things going."
Maholm gave up five runs, four earned, and eight hits in five innings and has permitted four runs or more in five of seven starts. Still, Tracy said there's no thought of moving him out of the rotation.
"He has starts where he gets into the counts he wants to be, but he's had difficulty making the pitches needed to put hitters away," Tracy said. "That fourth inning today was a reflection of that."
Jose Valverde, coming off a four-pitch save Saturday night, pitched the ninth for his 15th save, third in four games and second in 19 hours. Brandon Lyon preceded him with a scoreless eighth.
Snyder's double was only his second extra-base hit this month. ... Johnson is 9-5 against the Pirates but was 0-2 in PNC Park until Sunday. ... The Pirates went 4-6 on their homestand against the Braves, Marlins and Diamondbacks. The Diamondbacks were 5-4 on their road trip to Houston, Colorado and Pittsburgh. ... Maholm has lost five of seven ... LaRoche was 9-for-21 in his previous six games before going 0-for-4.