WASHINGTON, D.C. – Kenley Jansen could sense Jayson Werth gaining on his fastball, more precisely a cutter that travels at the velocity of and howls just like a four-seam fastball, and so could his catcher, Yasmani Grandal. Nearing the conclusion of a 4-3 victory for the Dodgers on Friday night over the Nationals, Jansen saw Werth’s eyes widen, saw him shifting his weight sooner, saw him locking in on 97 mph, on those few inches of right-to-left dodge at the end.

Jansen had thrown 1,002 pitches in the regular season. Something like 940 of them were cutters, or variations of the cutter, a few that straightened out and bucked like a four-seamer or inexplicably ran the other way. That’s the pitch that turned him from a catcher to a pitcher way back when, the pitch that has wrought 127 saves the past three seasons, the pitch that has made him rich and is weeks from making him much, much richer.

So, in fact, every pitch he’d thrown in Game 1 of the National League division series was that, a cutter, as hard as his 6-foot-5 and 270 pounds could propel it, because that’s what he does and for 15 or so minutes many nights, that’s who he is. It’s coming hard and fast and then right at the end when your eyes and brain can’t quite comprehend all of it anymore, it darts away.

Jansen had been waved in on this night five hitters before, with only one out in the eighth, with only that one-run lead, because Clayton Kershaw had lasted only five innings, which moved everybody’s shift up by at least an inning. In came Joe Blanton in the sixth, and that’s when Jansen decided this wouldn’t be one of those clean three-out jobs, when he decided the eighth inning just might be his too. In came Grant Dayton. In came Pedro Baez. And when Washington Nationals manager Dusty Baker summoned the left-handed hitters from his bench, in came as sure a thing as Los Angeles Dodgers manager Dave Roberts has.

Jansen would throw 26 cutters in a row, looking like a man swinging an ax. There was a two-out double in the eighth when Clint Robinson swung about 20 minutes late on one of those cutters, but otherwise there was only power and exactness and inevitability.

He sat down between the eighth and ninth innings, and the Dodgers loaded the bases in the top of the ninth. It was Jansen’s turn in the lineup, except Andre Ethier stood in the on-deck circle where Jansen should have been.

“A ruse,” Roberts said afterward.

Asked the chances Baker might actually have fallen for it, might’ve believed that Ethier would bat and someone other than Jansen would have the ninth, Roberts grinned and said, “Zero.”

“I figured,” he said, “I’d play it out.”

Walking back to the dugout, Ethier passed Jansen on the steps and said to Roberts, “Am I done then?”

Roberts smiled and nodded. Jansen struck out, returned to the dugout and dropped his helmet and bat on the top step. He was handed his cap and glove. He walked to the mound and struck out Trea Turner on three cutters. He had Bryce Harper line to second base on a sixth cutter. Along came Werth, a veteran with a clever mind and long arms and plenty of experience in moments where nearly 44,000 people are screaming and one run is all that is necessary. Daniel Murphy, an October hero only a year ago, was on deck. Werth could hit one in the seats and tie the game. He could punch a single the other way and get Murphy his shot. And Jansen went to work with the cutters to end it here, to avoid Murphy, to give the Dodgers their one-up lead in the best-of-five series.

The first was a ball, under the strike zone, at 96 mph. The second, at 95, Werth swung through. So it began. Werth fouled off the next, at 95. The count was one ball, two strikes. Sensing the end, throwing strikes, the ball light and perfect in his hand, Jansen puffed up and delivered the next cutter at 97, the exertion causing him to spin out and stumble to a knee. Werth fouled it off. Jansen threw another at 97, this time maintaining his balance. Werth fouled it back. The crowd groaned, then, feeling Werth gaining on that fastball, encouraged that his bat speed was sufficient and dangerous, cheered louder.

Jansen was 25 pitches in, 25 cutters in, the last five to Werth.

“I felt like he was getting adjusted on that fastball a little,” Jansen said.

Grandal asked for a slider. Jansen had thrown, oh, maybe 60 of them all season. It’s a good pitch, and yet not his best pitch, not by far. It’s a good pitch, and yet not the pitch he’d allow Werth to beat him on. Jansen shook it off.

Werth fouled another cutter, the sixth.

The scoreboard begged for noise. The crowd begged for contact. Dodgers and Nationals hung on the dugout rails. Somebody was going to have spent their best pitcher – Kershaw for the Dodgers, Max Scherzer for the Nationals – and lost in Game 1. The Dodgers had grinded for their four runs – a Corey Seager home run in the first, a Chase Utley RBI single and a Justin Turner two-run homer in the third. The Nationals had answered off Kershaw – an Anthony Rendon two-run single in the third, a Trea Turner sacrifice fly in the fourth. Four to three, and that stood for all but one final out, one final swing.

Grandal asked for one last cutter. Jansen shook his head, almost imperceptibly. The slider.

“Well,” Jansen said, “I feel like it was perfect timing. I just tried to keep, you know, keep him swinging, kind of swing happy. That’s how I feel like on that one. I’ve just got to slow him down. I didn’t think about a punch-out right there. I think even to show it, so I can make my next pitch more effective to him.”

Grandal settled in behind the plate, leaned a bit to his right in expectation of the slider that would bite hard and, he hoped, die in the dirt a foot in front of his mitt.

“Seemed like [Werth] had started getting on that fastball,” Grandal said. “He’s a veteran guy. He knows what his strengths are.”

“Yas knows what he’s doing,” Jansen said.

Jansen took his slider grip, hidden in his glove. He could not make a mistake. He could not hang it. Werth would hit that 450 feet, even if he’d been surprised by it. He thought of none of those things. He thought only of bouncing that slider, of setting up the next pitch, of getting Werth off the next pitch, which most certainly would be another cutter.

Instead, that slider struck out Werth. Swung right over the top of it. Ended the game right there, 26 cutters and one slider after Jansen had walked in, ended it on that 85-mph slider that was not Jansen’s best pitch, but only his perfect pitch.