Brett Wallace and Fernando Martinez each hit three-run homers to back Lucas Harrell’s eight strong innings and the Houston Astros beat the Cubs 10-1 on Tuesday night.Harrell (10-8) scattered six hits and struck out six, helping the Astros win for only the third time in their last 28 road games. Harrell has allowed two runs or fewer in all seven of his starts since the All-Star break.Scott Moore added a solo shot and double twice for a career-high three extra-base hits. Jose Altuve doubled twice and had three of Houston’s 13 hits.Chris Volstad (0-9) lasted just five innings, allowing eight hits and four runs in his latest bid for his first big league win since July 10, 2011. He hasn’t won in his last 23 starts and is approaching the major league record of 28 held by Cliff Curtis, Matt Keough and Jo-Jo Reyes.Volstad fell to 0-14 with a 5.51 ERA during his winless skid.Darwin Barney drove in the Cub’s run with a fielder’s choice in the seventh.The Cubs have lost 12 of 14 and matched their season high by falling 25 games under .500, their worst record since finishing the 2006 season 30 games below break-even.Harrell retired the first eight Cubs before Volstad singled with two outs in the third, his first hit of the season. Harrell induced two double plays and nearly got a third when Barney just beat Tyler Greene’s relay in the seventh, allowing Starlin Castro to score.Harrell got plenty of support in Houston’s biggest offensive outburst since scoring 11 runs at U.S.Cellular Field on June 10 against the White Sox. Houston had scored just 11 runs combined in its last six losses on the road.Wallace’s homer to dead center in third gave Harrell an early cushion. Martinez’s drive to almost the same spot in the sixth broke the game open. It was Martinez’s first homer of the season. He was recalled from Triple-A Round Rock on Friday.Houston’s five-run sixth was inning aided by Castro’s error on a sure double-play ball, his 18th miscue of the season. He tied Pittsburgh third baseman Pedro Alvarez for the most errors in the majors.Moore doubled in Altuve in the first to open the scoring and kick off his best night as a big leaguer. Moore, who broke into the majors with the Cubs in 2006, doubled and scored in the sixth and hit a solo homer to right in the seventh.

NOTES—Astros manager Brad Mills said RHP Francisco Cordero (sprained ligament in toe) likely won’t return until Sept. 1. … The Cubs announced that Albert Almora, their top pick in June’s draft, had been promoted from rookie league Mesa, Ariz., to Class-A Boise. Almora, 18, hit .347 with one homer, 13 RBIs and five steals in 18 games for Mesa. … Dale Sveum said Matt Garza had not been ruled out for the season, but was still more than a week away from resuming throwing.