"Yeah, it's nice, especially in a game like that, tough pitch, low and away," Fielder said. "I'm very happy with it."
Fielder is the 13th active player with 1,000 RBIs in his career and 281st all-time.
"You look up and see the numbers and where he's at, it's a testament to him," Rangers manager Jeff Banister said. "You've got to be in the game for awhile and you've got to hunt RBI. I have been on the other side [with Pittsburgh] of a lot of those RBI. I am happy to be on the same side."
Cecil Fielder had 1,008 RBIs so he and Prince are only the second father/son tandem to both reach 1,000. The other is Barry and Bobby Bonds.
"That's a big deal, having something in common with those guys," Fielder said.
The Rangers' sixth-inning rally started with a walk by Rougned Odor and a single by Nomar Mazara. Adrian Beltre then grounded into a double play with Odor moving to third.
That gave Santiago a chance to get out of the inning and he couldn't do it. Fielder singled up the middle to tie the game with the 1,000th RBI.
"It's good very good, but I've got more," Fielder said. "Hopefully a lot more."
Ian Desmond followed with a double into the left-field corner. Fielder was running on the full-count pitch but it was still a gamble for third base coach Spike Owen to send him home. It worked as the relay throw from shortstop Andrelton Simmons was off target.
"That was even better," Fielder said. "I was in motion. I had good momentum and I couldn't stop. Once I'm at third, there is no stop. I'm going through that stop sign. There is too much of that mass times whatever…too much of that to stop."
Mitch Moreland's single drove home Desmond to give the Rangers a 4-2 lead.
T.R. Sullivan is a reporter for MLB.com. Read his blog, Postcards from Elysian Fields, follow him on Twitter @Sullivan_Ranger and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.