Trayvon Robinson left no doubt what was on his mind as he left his feet in the fourth inning for a ball hit down the left-field line.

Outfielders won't risk diving for sinking liners that early unless something is at stake, and the 12 batters in a row ultimately retired by Hisashi Iwakuma to open Friday night's game certainly counted as that. Iwakuma got only one out further in his bid to duplicate Felix Hernandez's perfect game, but was good enough when it mattered to prevail 5-3 over the Minnesota Twins in a contest that wasn't as close as the final score.

The Mariners ran their streak of consecutive batters retired to 42 — the longest stretch by any team since at least 1974 — and continued what has been a strong second-half surge by their starting pitchers.

"I said, 'Hey, why not take a shot at it, take a chance?' " Robinson said. "Luckily, I stayed low enough to make a good judgment and just went after it."

The catch was the second out of the fourth inning and earned a rousing applause from 22,602 fans at Safeco Field, many of which were no doubt thinking the Mariners might become the first club in history to record consecutive perfect games. They continued the cheers as Iwakuma notched the final out of the fourth, extending Seattle's scoreless innings-pitched streak to 21.

"It's awesome," Robinson said of the team's pitchers. "It seems like all we've got to do is score two runs for our pitching staff. The pitchers have been great."

Seattle looked to have all the runs it would need the first two innings. John Jaso continued a red-hot stretch of second-half hitting with a two-run homer to right field in the first off Nick Blackburn, then Miguel Olivo added a solo shot in the second for a 3-0 lead.

The Twins finally got a base runner when Justin Morneau doubled to the right-field corner to lead off the fifth and end Seattle's streak of batters retired, dating to the ninth inning of Tuesday's contest against Tampa Bay. All of a sudden, the game turned serious when a Brendan Ryan error eventually led to an unearned Minnesota run on an ensuing Matt Carson single.

With the lead cut to 3-1, a walk allowed the Twins to load the bases with only one out. That's when Iwakuma hunkered down and struck out Pedro Florimon and Darin Mastroianni to end the last real threat the Twins would have.

Robinson and Eric Thames hit back-to-back doubles in the sixth for a fourth Seattle run and a single by Dustin Ackley off Blackburn made it a 5-1 game. Iwakuma bowed out with that same lead after seven innings, having scattered four hits with no earned runs allowed.

The Twins woke up briefly in the eighth with consecutive homers by Joe Mauer and Josh Willingham off Stephen Pryor. But Lucas Luetge got the final out of that frame and Tom Wilhelmsen retired the side in order in the ninth for the save.

Iwakuma agreed the key was his ability to focus in the fifth.

"Because of my experience, I was able to calm down and just concentrate on striking out the hitters," Iwakuma said through interpreter Daisuke Sekiba.

Iwakuma admitted he'd tried to use Hernandez's perfect game to inspire him.

"I saw him pitch, and it was really awesome," he said. "So, today I tried to pitch like him in the first inning to get into the game."

Iwakuma said he wasn't thinking about it much as the early innings rolled on.

"I tried to finish off the first hitter every inning to have a good game," he said. "And I did it the first four innings."

Mariners pitching coach Carl Willis has been mighty impressed by the second-half roll his pitchers have been on. The Mariners have won 10 of 11 at home and are 20-13 (.606) overall since the break, largely because of their pitching.

"You know the old cliché of how hitting is contagious, well I think pitching is that way, too," Willis said. "I think a big part of it is, these guys really like each other and they're not out there trying to one-up anybody. One guy goes out and does his job, and the next one wants to keep it going."

Mariners manager Eric Wedge said he wasn't thinking about perfect games once the Twins loaded the bases in the fifth inning. Wedge merely needed Iwakuma to be good enough to survive the frame with the lead intact.

"That's where you see his experience come into play," Wedge said. "You can tell this guy pitched for quite a while over in Japan. He doesn't get rattled in those situations. He really settles down, works to execute pitches. He doesn't get caught up in the situation and just basically works at what he can control, which is to execute pitches."

Geoff Baker: 206-464-8286 or gbaker@seattletimes.com