The centerpiece acquisition in the trade that sent pitcher Ubaldo Jimenez to Cleveland for four players, Pomeranz, 22, did that and then some, working five scoreless innings as the Rockies beat the Reds, 4-1.
"That's what we were looking for," said Gonzalez, who was scratched from the lineup with back soreness. "It was really good. He's our future."
Pomeranz allowed two singles, both by Chris Valaika and one of them an infield hit. He walked two, struck out two, hit one batter and threw 63 pitches, 36 for strikes. He got nine of his outs on ground balls, and got Chris Heisey in the second and Edgar Renteria in the third to ground into double plays.
"We had him [in] trouble a couple of times," Reds manager Dusty Baker said. "But he threw a couple sinkers and got out of trouble. We only got two hits off him; you have to be impressed.
"The sinker is his best pitch. He threw some decent breaking balls, but his main pitch was the sinker. That's what you need here."
Pomeranz joined the Rockies on Tuesday, but wasn't activated until Sunday. Rockies manager Jim Tracy said he noticed no change in Pomeranz on the mound from what he first saw when Pomeranz showed up in the Rockies clubhouse.
"I see a very, very slow heartbeat," Tracy said. "It's very encouraging to see actually.
"He's a strike-thrower. His delivery is very, very clean, and he has a quick arm. And a quick arm like that creates a lot of deception, not only for left-handed hitters but right-handed hitters -- 91-92 [mph] looks much firmer because of that."
Pomeranz said after he left the game he noticed the surroundings more than he did when he was on the mound concentrating on the task at hand.
"It was pretty exciting being out there," Pomeranz said. "But mentally, I just took it like any other game I pitched this whole year. You just got to execute a little better. That's what I went out there thinking, and it ended up well for me."
Ty Wigginton, who wasn't in the lineup until Gonzalez was scratched, homered in the fourth to give Pomeranz a 1-0 lead. It was Wigginton's 15th homer and first in 62 at-bats.
The Rockies added a run in the fifth when Eric Young Jr., playing second base for the first time since July 23, singled with one out, stole second and third and scored on a two-out single by Pacheco, who made his Major League debut at first base after three starts at third.
Young again used his speed to set up the first of two Rockies' runs in the seventh. He led off with a bunt single, stole second -- his 21st steal in 23 attempts this season -- moved to third on Dexter Fowler's single to short right and scored on catcher Ramon Hernandez's passed ball. Fowler took second, moved to third on a ground out and scored on Kevin Kouzmanoff's slow roller to second base.
Jason Hammel relieved Pomeranz and pitched the final four innings to earn his third save in the Majors and first since Sept. 28, 2008, when he was with Tampa Bay. Hammel allowed two hits, including Joey Votto's homer in the ninth that ended the shutout bid.
Pomeranz, the fifth overall pick in the 2010 draft, took a strange, circuitous path from the Indians to the Rockies and his Major League debut.
Players can't be traded until one year after they sign their first professional contract. That meant Pomeranz had to spend two-plus weeks in limbo working out at the Indians spring training complex in Goodyear, Ariz., before he could report to the Rockies Double-A Tulsa affiliate.
In his Tulsa debut on Aug. 17, Pomeranz took a perfect game into the seventh and finished with seven scoreless innings, allowing two hits and throwing 78 pitches with no walks and four strikeouts. Three days later, Pomeranz underwent an emergency appendectomy.
He returned Sept. 5 and threw three perfect innings with three strikeouts before heading off to the Rockies, where he was working today under a 65-pitch limit.
"I was pretty pumped up there at the beginning," Pomeranz said. "I felt the best [in] the fourth and fifth innings when I got settled down a little bit, got the early game jitters out of the way. I really wasn't too nervous out there. I was more nervous about that first at-bat than I was actually [about] pitching."
That first time at the plate? It came in the third and Pomeranz sacrificed. Then it was back to the dugout to concentrate on the middle of the Reds lineup, which Pomeranz retired in order in the fourth.
"My curveball was a little iffy early, but I threw it for strikes when I needed to. Everything kind of came together towards the end once I harnessed everything. I didn't have much use for my changeup in the Minor Leagues, so I didn't throw it very often. But I still had it in my back pocket. Used it today."