WASHINGTON — Nick Senzel made a leaping catch against the right field wall to save a run in the ninth inning, then hit a two-run homer leading off the 10th to lift the Cincinnati Reds over the Nationals 5-4 Thursday for their first series sweep at Washington since 2008.

Cincinnati (49-39) stretched its winning streak to five with the four-game sweep that maintained a two-game lead over the second-place Brewers in the NL Central heading into a weekend series at Milwaukee. The Reds have won 20 of their last 24 games overall and 19 of their last 22 on the road, moving 10 games over .500 for the first time since Aug. 29, 2021. They also host the Brewers in a three-game series the weekend after the All-Star break.

“It was important for us to focus game to game here, especially this last one,” Senzel said. “It just brought some crazy delays and slow pace and hot and humid, just kind of how D.C. is. We kept fighting to the end. We knew how important it was for us to take care of business, and now it’s time to go to Milwaukee and the All-Star break on a good note.”

Senzel said he felt he needed to make up for allowing Riley Adams’ single to fall starting a two-run fifth. He started with a leaping catch on CJ Abrams with the sun in his eyes for the second out of the ninth after Adams’ one-out double off Tony Santillan (1-0), who worked a scoreless inning in his first Reds appearance since June 13, 2022.

“It’s one of the best plays I’ve ever seen, for that ball to be able to stick in his glove like that,” Cincinnati manager David Bell said. “He has great hands wherever he is on the field. With the game on the line, that’s the game right there.”

With Tyler Stephenson on second as the automatic runner, Senzel gave Cincinnati a 5-3 lead when he homered on a first-pitch fastball from Hunter Harvey (3-4).

“He made a nice catch and he comes up and hits a big home run for them,” Washington manager Dave Martinez said.

Alexis Díaz earned his 25th save in 26 chances, allowing an RBI single to Lane Thomas before retiring Keibert Ruiz on a game-ending flyout with runners on second and third.

Playing exactly one month after his major league debut, Elly De La Cruz had two hits and finished the series 10 for 18. The third baseman went into foul territory and made a 95.6 mph throw to first on Adams’ grounder for the final out of the sixth, the fastest throw for an infield assist in the major leagues this season and the fastest for the Reds since Statcast began tracking in 2015.

Cincinnati is 22-6 since bringing up the 21-year-old, who is hitting .325 with four homers, 15 RBIs, 12 stolen bases and a .905 OPS.

Last-place Washington (34-53) fell to an NL-worst 13-31 at home and has lost 14 of 15 at Nationals Park since June 3.

Washington starter MacKenzie Gore pitched 1 1/3 scoreless innings and was removed after a 1-hour, 43-minute rain delay, Cincinnati’s Brandon Williamson remained after the delay and pitched three shutout innings with four strikeouts.