It was suspiciously fitting that Dallas quarterback Tony Romo threw out the ceremonial first pitch Wednesday night.

The Seahawks and Cowboys don’t face off until Sept. 16, but the Mariners and Rangers decided to pay homage to their gridiron neighbors anyway, as the Mariners dismantled Texas 21-8 at the Ballpark in Arlington to win a second consecutive series over the AL West leaders, falling a run short of their single-game record set in 1999.

Kyle Seager collected a pair of singles and two doubles, Justin Smoak hit two three-run home runs, Dustin Ackley had a three-run dinger and Jesus Montero smashed an opposite-field home run as the club posted the most runs in a single game in the majors this season.

This was the same team that was victimized by a perfect game from Philip Humber of Chicago, where Seattle plays a three-game series starting Friday.

The Mariners, whose team batting average of .229 was 13th in th AL, had 20 hits. Following a 10-3 win Tuesday, the Mariners scored one more run in the past two games than they had in the nine previous combined (30).

Despite entering the night with a 6-1 career record against Seattle, the Mariners chased starting pitcher Derek Holland in the second inning. The Texas southpaw lasted just an inning and two-thirds, getting pasted for eight runs on eight hits. In back-to-back games, the Mariners scored 31 runs.

“I think we’re just going up there and everyone has got their own approach and they’re  sticking to it,” Smoak told ROOT Sports.  ”Early on Holland — he’s a great pitcher, and the first inning he was right on.  The second and third we kind of got to him.”

The onslaught started innocently in the second after Montero blooped a single into right field.  Smoak followed with a double down the left-field line.  After Alex Liddi grounded out to first, Miguel Olivo lined a 3-1 pitch into left field to give the Mariners a 2-0 lead.

After another out, Brendan Ryan reignited the rally with a single. With runners on the corners, Ackley smashed a line drive around the foul pole and into the bleachers to tack on three more.

Chone Figgins, starting in right field as Ichiro took his first game off of the season, singled and stole second. Seager followed with an RBI single before Montero added to Holland’s horrific start with a two-run blast into the Texas bullpen to give Seattle a 8-0 lead.

After Mariners starting pitcher Blake Beavan worked his way around a lead-off double from Adrian Beltre in the bottom of the frame, the Mariners doubled their run production in the third.

Facing Texas long reliever Yoshinori Tateyama, Saunders lined a double into the gap to lead off the inning for one of his three hits.  Shortstop Alberto Gonzalez airmailed a routine ground ball from Ryan into the camera well, scoring Saunders for a 9-0 lead.

Montero followed with his third hit in two innings, taking Tateyama off the wall in left-cenervto drive in two more.  Still with only one out, Smoak continued to his recent power surge with a towering blast into the Rangers bullpen to give Seattle a staggering 14-0 lead. The switch-hitting first baseman finished  3-5 with six RBIs to raise his average to .231.

Seattle picked up three more hits to lead 16-0 while the near sellout crowd sat stunned. The Mariners added one in the fourth and four in the eighth, thanks in large part to another three-run blast from Smoak to cap.

Meanwhile, Beavan held down the potent Rangers lineup for five scoreless innings until the Rangers tagged him with a five-spot in the sixth.  Despite the late-game struggles, the native Texan still managed to scatter eight hits over six innings while striking out two to pick up his third win.

With an off-day Thursday before taking on the White Sox over the weekend, manager Eric Wedge said he was pleased with the way his young team didn’t lose focus after taking a 16-run lead.

“I was particularly pleased they came back and scored more runs later in the ball game after (Texas) scored a few runs,” Wedge said.  ”That meant a lot to me.  I think that says a lot about our guys too.  this ballpark against that team you always have to keep going.”

DELABAR DEMOTED – Relief pitcher Steve Delabar, who has given up seven home runs in 24.1 innnings pitched, was optioned to AAA Tacoma after Wednesday’s game. No roster replacement was named.

Delabar, 28, wasi1-1 with a 5.18 ERA in a team-high 25 relief appearances.  He made his major league debut with the Mariners last season after being out of affiliated professional baseball since 2008.