SAN DIEGO -- Jason Marquis would like to put to rest any talk of him being just a first-half pitcher.
Making his initial start of the second half, Marquis looked very much like the guy who was one of baseball's best before the All-Star break.
Marquis, who has a first-half record of 60-39 in 10 seasons, is ready to improve the career numbers that show he's a sub-.500 pitcher in the second half.
"There's no guarantee in anything, especially baseball," he said. "You look back, see what went wrong, whether it's from a physical standpoint or a mental standpoint and try and get better."
San Diego had no answers for Marquis (12-6), who has a career mark of 30-37 in the second half. He was dominant with a sinker and cutter that produced 16 ground ball outs.
"If today is any indication of what his second half is going to be like, we'll take it," Rockies manager Jim Tracy said.
"It's big for us to come here and win three of four," Stewart said. "We're still right in there and it's huge to come out strong like this."
Colorado ruined the major league debut of San Diego right-hander Mat Latos (0-1), the club's top pitching prospect. Latos allowed two runs and three hits, struck out four and walked one in four innings.
After the game, the Padres traded right-handed reliever Cla Meredith to Baltimore for infielder Oscar Salazar. The deal came one day after San Diego infielder Edgar Gonzalez was beaned by a 93 mph fastball from Colorado's Jason Hammel.
Gonzalez remained hospitalized on Sunday and is expected to go on the 15-day disabled list. Although he did not suffer any skull fractures or a concussion, Gonzalez still had dizziness, ringing in his ears and a partial loss of hearing.
Marquis pitched well despite a little irritation in his right index finger. The right-hander allowed five hits and was never seriously threatened by San Diego, last in the majors in runs and batting average.
Marquis was selected to the All-Star team for the first time, but did not pitch in the game Tuesday night. He allowed only two runners to reach second base through six innings.
"I worked the bottom of the zone," Marquis said. "Me and [catcher] Chris [Iannetta] had a good plan and knew that we wanted to attack."
Marquis struck out three and did not walk a batter.
"What he did today was to pound the strike zone early in the count," Tracy said. "That is what has taken him to where he is today. This is when Jason Marquis is at his best. He was in complete control."
The 21-year-old Latos regularly threw his fastball in the mid to upper 90s (mph), including a couple of pitches at 98 mph. But he got into trouble in the first inning when he needed 25 pitches to get out of the inning, including Todd Helton's 12-pitch at-bat. Latos was on a pitch count because of past shoulder problems and left after 75 pitches.
"I was a little nervous, but I was fine," Latos said. "In the first inning, I felt like I was going to get sick on the mound. Second, third and fourth innings, the same thing."
Stewart, who returned after missing Saturday night's game with soreness behind his left knee, hit a 430-foot homer in the fourth for a 2-0 lead.
Hawpe added his 15th home run in the sixth when the Rockies scored four times, capped by Marquis' two-run double.
Latos was a combined 8-1 with a 1.38 ERA at Double-A San Antonio and Class-A Fort Wayne. He was selected to the Futures Game during All-Star week in St. Louis.
Kevin Kouzmanoff hit a sacrifice fly in the seventh for the Padres, who scored one run or less for the fifth time in seven games. San Diego has the worst record in the majors since June 1 at 12-30.
At 21 years, 222 days, Latos is the fifth-youngest Padres pitcher to make his major league debut. ... Padres C Jose Lobaton got his first major league hit with an eighth-inning single. ... Colorado's starting pitchers have not allowed a home run in nine straight games. ... San Diego was attempting to win consecutive home games for the first time since taking nine straight May 15-24.