Tomas had six balls hit to him by the Rockies and he fielded five cleanly while misplaying one that was still ruled a hit.
"He had one tough play that maybe he could have made the play on," D-backs manager Chip Hale said. "It was not an easy play. I think he got a little confused whether he should backhand or forehand. Those other plays were tremendous."
Tomas did a nice job barehanding a bunt in the fourth, making an off-balance throw to first base for the out.
"I was ready for the guy to bunt so I was close," Tomas said. "It happened and I was ready for that. With all the preparation I do every single day that's one of the reasons why today I did well."
Tomas was 0-for-3 at the plate.
Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.