Trouble is, D.J. LeMahieu, running on the pitch, was about to score all the way from first.
The relay from shortstop Chris Owings beat LeMahieu to the plate, but catcher Miguel Montero couldn't hang onto the low throw and LeMahieu slid across with the go-ahead run.
Rockies manager Walt Weiss praised both LeMahieu and third base coach Stu Cole.
''D.J.'s got to give Stu the opportunity to wave him and that's what he did. He never slowed down and gave Stu the opportunity to make a gutsy call,'' Weiss said after Colorado's come-from-behind 9-4 victory Saturday night.
''It still seemed like we had the runner beat with the throw but we didn't hold on to it,'' manager Kirk Gibson lamented after the Diamondbacks' fourth straight loss left them with a 1-7 record and their worst start in franchise history. ''It was a pressure play they put on us. We didn't execute it.''
Gonzalez was as surprised as the D-Backs were when he looked back and saw LeMahieu huffing for home.
''It was awesome, a heads-up play,'' Gonzalez said. ''Parra kind of falls asleep in right field thinking that I was going to go to second base, throws the ball to second base, D.J. never stopped and that was the go-ahead run, that was what we needed. And once again, the bullpen did an amazing job tonight holding the opposing team and we just kept scoring runs.''
After falling behind 4-0, the Rockies scored the game's final nine runs for their second straight blowout of the reeling D-Backs.
Nolan Arenado homered twice for his first career multi-homer game, Michael Cuddyer went deep, rookie right-hander Tommy Kahnle picked up his first major league victory, Charlie Blackmon went 3 for 4, tying the Rockies' franchise record with nine hits in consecutive games, and Colorado snapped Paul Goldschmidt's 26-game hitting streak that was the longest in the majors.
Yet, it was LeMahieu's hustle play that truly epitomized the Rockies' successful night.
It's the kind of aggressiveness on the base paths Weiss has been preaching about all spring that will be required of his team if the Rockies are going to have the kind of season their owner thinks they can. He predicted a 90-win season in the competitive NL West.
Never looking back, LeMahieu didn't see where Gonzalez had hit the ball, ''but I could kind of see by Stu's body language that if something happened, if he bobbled it or whatever, that we could take an extra base there. It was a great call by him.''
Gonzalez praised both Cole and LeMahieu with his most improbable of RBIs.
''He thanked me for my hustle and getting him that RBI,'' LeMahieu said with a chuckle. ''It feels good as a teammate to pick up an RBI for a guy like that.''
That hustle also benefited Kahnle (1-0), who was selected in the 2013 Rule 5 draft from the New York Yankees. He pitched 1 2-3 innings of one-hit ball in relief of starter Jorge De La Rosa, who struggled through his second straight start.
Brandon McCarthy (0-1) surrendered six earned runs on seven hits in six innings for Arizona.
The Rockies fell behind 4-0 before scoring three times in the fourth and twice in the fifth to take the lead.
De La Rosa allowed four runs, three of them earned, on four hits. He struggled through a 42-pitch, 21-minute first inning but only gave up one run on Martin Prado's double into the left-field corner that scored Goldschmidt from first. He also gave up a two-run homer to Mark Trumbo, his fourth, in the third inning.
Notes: Goldschmidt went 0-for-2 with two walks. ... Blackmon's nine hits in two games tied the franchise mark set by Juan Pierre in 2002. ... Trumbo now has four home runs and 11 RBIs in five career games at Coors Field. ... De La Rosa threw 101 pitches, 30 more than McCarthy threw in six full innings. ... Colorado SS Troy Tulowitzki took a designated day off. ... The series wraps up Sunday afternoon with the D-Backs sending LHP Wade Miley (1-1) against LHP Brett Anderson (0-1).
Follow AP Sports Writer Arnie Melendrez Stapleton on Twitter: http://twitter.com/arniestapleton