KANSAS CITY (Interstat) — Yordan Alvarez hit two home runs in the first inning, including a grand slam, and the Houston Astros withstood a furious Kansas City Royals rally Friday night to win 10-8 at Kauffman Stadium.

The Astros, who entered the game with a 31-39 record and had lost their previous two games, sent 13 batters to the plate in a nine-run first inning. The Royals matched that with five runs of their own in the bottom of the first, but Houston added an insurance run in the ninth on a pinch-hit home run by Brice Matthews and held on.

Nate Pearson pitched a scoreless inning of relief to earn his first win of the season. Luinder Avila took the loss for Kansas City, dropping to 1-3. Josh Hader pitched a perfect ninth inning for his second save.

The game started explosively. Houston leadoff hitter Jeremy Peña singled, and Alvarez followed by crushing a 23rd home run of the season to left field, scoring Peña. Christian Walker then hit his 17th home run, a solo shot, to make it 3-0. After two quick outs, Joey Loperfido walked, Cam Smith singled and reached second on a throwing error by shortstop Bobby Witt Jr., and Taylor Trammell singled to drive in Loperfido. A walk to Christian Vázquez loaded the bases, and Peña walked to force in another run. Alvarez stepped in again and launched a grand slam to center field, his 24th home run, giving Houston a 9-0 lead. Walker struck out to end the inning.

The Royals answered immediately. Carter Jensen singled, Witt walked, and Vinnie Pasquantino singled to drive in Jensen. Maikel Garcia grounded into a force out that scored Witt, and Jac Caglianone struck out. Salvador Perez singled to put runners at the corners, and Michael Massey doubled off the right-field wall to score Garcia. Kameron Misner then singled to center, bringing home Perez and Massey, and the Royals pulled within 9-5. Isaac Collins singled to left, but Misner was thrown out trying to advance to third, ending the inning.

Both teams settled into a pitchers’ duel after that. Houston’s Steven Okert threw 2 1/3 scoreless innings, allowing three hits, and AJ Blubaugh added two scoreless innings with two strikeouts. The Astros’ bullpen kept Kansas City off the board through the seventh, while the Royals’ relievers held Houston scoreless.

In the eighth, the Royals mounted a comeback. Enyel De Los Santos entered for Houston and gave up three runs on three hits. Garcia singled, Perez singled, and Massey singled to drive in Garcia. After Lane Thomas struck out, Isaac Collins was hit by a pitch to load the bases. Carter Jensen walked to force in Perez, cutting the lead to 9-7. Witt then singled to shortstop, with the ball deflected by third baseman Isaac Paredes, scoring Massey to make it 9-8. Starling Marte grounded out to end the inning, but the Royals had erased all but one run.

In the top of the ninth, Houston got breathing room. With one out, Matthews pinch-hit for catcher Christian Vázquez and homered to left field, his fifth of the season, restoring a two-run lead. Cam Smith lined out and Jake Meyers flied out to end the inning.

Hader closed the door in the bottom of the ninth, retiring Maikel Garcia on a flyout, Jac Caglianone on a popout, and Salvador Perez on a groundout to first base.

Houston outhit Kansas City 10-13, but the Astros capitalized on early walks and errors. Alvarez finished 2-for-5 with two home runs and six RBIs. Trammell went 2-for-3 with an RBI and a double. Matthews was 1-for-1. For Kansas City, Massey doubled and drove in two runs, and Jensen reached base three times with a single and two walks.

The win moved Houston to 32-39, while Kansas City fell to 28-42. The two teams meet again Saturday in the second game of the series.

Interstat’s game simulator had projected a final score of Houston 6, Kansas City 5. The ELO system gave Kansas City a 50.9 percent probability to win. Houston was installed as a pregame favorite with a spread of minus 1.5. The total of 18 runs went under the over-under line of 9.