While introductions were being made on the first tee, Matt Kuchar, who tied for third at the 2012 Masters for his best finish in a major, was carding a birdie on that hole to move within a shot of leader Dufner, at 8-under par.

Justin Rose missed a long par putt on the second hole and his shoulders slumped in a tired sort of way as he dropped four shots behind the Dufner.

Jim Furyk’s purple shirt is perfect. His approach to the first green, not so much.

Scott, meanwhile, birdied No. 1 and gave an early fist pump. Whatcha got to follow up Dufner? A birdie putt that just touches the edge of the cup and turns into a par. Dufner now leads Scott and Kuchar by a shot.

The leaders are off and don’t seem nervous.

Well, except for Furyk, who bogeyed the second hole to fall three shots off the lead.

Justin Rose keeps getting in trouble. He drove 70 yards left on the par-three third. He did make it on the green but the putt will be long for par and it will also be long for bogey.

Rory McIlroy moved back under par with a birdie on the par-five 13th and when he birdied the 17th, he got to 3-under and into the conversation for the final day.

Meanwhile, Dufner started out with four consecutive pars and not a single expression change on his face.

Webb Simpson, who had a 64 on Friday, cards a triple bogey at No. 5 to go 6-over for the day.

The par-three third hole was taking its toll. Kuchar double bogeyed and fell three shots behind Dufner. We’ll let you know when Dufner’s facial muscles move.

--Diane Pucin

Leader Jason Dufner, contenders on course | 11:55 a.m.

Now, maybe, “Dufnering” can go from viral to mainstream.

With Jason Dufner scheduled to tee off just before noon PDT at the PGA Championship, leading the pack at 9-under, more sports fans might get to know the Ohio golfer and the art of impersonating his laconic style.

Dufner seems to wear the same facial expression whether sinking a putt for eagle or hooking a tee shot into the trees. Earlier this year, social media circulated photos of him doing concentration exercises with grade-school kids.

One snapshot showed Dufner sitting against a wall, arms at his side, face blank. “Dufnering” was born.

This week at Oak Hill Country Club in Rochester, N.Y., tournament officials struck the pose and fans cheered as Dufner -- showing almost no expression -- shot his way to a 63 on Friday, tying the record for lowest round in a major championship.

“I’m probably like everybody else,” he said. “But I can hide it a little better.”

Saturday’s third round will show whether he can continue to master his emotions – and his game – as the front-runner in a major. The likes of Adam Scott, Matt Kuchar and Jim Furyk are chasing just behind.