With the bases loaded, Wigginton ripped a shot off reliever Jose Veras (0-1) and past diving third baseman Pedro Alvarez into the left-field corner.
The Pirates took a 2-1 lead in the second inning when Ryan Doumit to center on a full count, scoring Lyle Overbay.
Colorado tied the game in the third and took a 3-2 lead on Seth Smith’s sixth inning solo homerun.
The Pirates knotted things an inning later after Doumit hit a one-out double. Matt Diaz, pinch-hitting for Garrett Jones, singled to right, scoring pinch-runner Ronny Cedeno.
In the eighth, however, Jose Veras replaced starter Charlie Morton on the mound and opened the inning by issuing a walk to second baseman Jonathan Herrera and a single to Carlos Gonzalez singled to center. It looked as if Veras might get out of the jam when he struck out Troy Tulowitzki and Smith back-to-back, but he hit Jose Lopez to load the bases before Wigginton’s double to left cleared the bases. Daniel McCutchen came on to end the inning, striking out Jose Morales.
Jose Tabata homered to center on a 1-2 count to give the Pirates life in the eighth, but .
Morton gave the Pirates a second consecutive solid start, pitching seven innings and allowing three runs, just two of which were earned.
Veras took the loss, allowing two hits, a walk and three runs in 2/3 of an inning.
Doumit and Diaz each had two hits for Pittsburgh.
At 5-2, the Rockies have tied the 1998 team for the second-best start in franchise history.
Both of Colorado’s losses have been in extra innings, including a 4-3 setback in 14 on Friday. Matt Belisle (1-0), one of eight pitchers used by Colorado manager Jim Tracy in that 5-hour-plus marathon, got the win.
James McDonald makes his second start of the season Sunday afternoon against Colorado’s Jhoulys Chacin.