Anthony strikes helping Washington Nationals get past Miami Marlins on Monday
Rendon went 2-for-4 with a two-run homer and a two-run double. He has 23 homers and 42 doubles this season.
Washington's Stephen Strasburg was in line for his 10th win of the season, but he walked four batters in four innings and was removed after his pitch count reached 100. He allowed three hits and one run in four innings.
Miami rookie starter Sandy Alcantara (2-2) took the loss, allowing seven hits, five walks, and six runs in four innings. He fanned three. His ERA went up from 2.35 to 4.00 in his fifth and least successful start.
It took just two batters for Miami to take the lead. Leadoff hitter JT Riddle singled and scored when Miguel Rojas doubled to the left-center gap.
However, Washington took a 2-1 lead in the bottom of the first. Adam Eaton drew a full-count walk and advanced to third on an opposite-field double by Bryce Harper. Both runners scored on a double by Rendon, who connected on a first-pitch fastball.
In the second, Miami had a chance to take the lead, but All-Star catcher J.T. Realmuto struck out looking with two outs and the bases loaded.
Washington wasted a similar bases-loaded opportunity in the third as Wilmer Difo grounded out to end the threat.
The Nationals broke the game open with four runs in the fourth, taking a 6-1 lead. Eaton walked and Trea Turner doubled before Washington cashed in with a Harper sacrifice fly, Rendon's homer and a solo shot by rookie Juan Soto.
Miami cut its deficit to 6-2 with an unearned run in the fifth. A fielding error by Nationals first baseman Mark Reynolds ultimately led to Brian Anderson's RBI single.
Matt Wieters won an eight-pitch battle with reliever Javy Guerra in the bottom of the fifth, slugging a solo homer to left-center.
Miami came back again, pulling within 7-3 in the seventh. Peter O'Brien hit a leadoff double, went to third on a grounder and scored on Lewis Brinson's RBI groundout.