On July 5, 2000 The Diamondbacks trip the Astros, 12 – 9. Arizona OF Luis Gonzalez becomes the first Diamondback to hit for the cycle. It is the first time the feat is accomplished in new Enron Field. Gonzalez is just the 9th player to both hit for the cycle and have a 30+ game hitting streak during his career.
Source
Baseball Reference July 5