Padraig Harrington cruised along in Steve Marino’s slipstream to keep his hopes alive of a maiden win in the AT&T Pebble Beach National Pro-Am.

But he knows he should have finished even closer to the lead after a picture perfect day on the Monterey Peninsula.

Marino was just two shots ahead of playing partner Harrington with six to play at Pebble Beach before he put in a late birdie burst to leave the Dubliner trailing by six shots at the halfway stage.

As Marino played his last six holes in three under to post a six under 66 and open up a four-shot lead over DA Points on 13 under par, Harrington failed to repeat his front nine fireworks as he covered the same stretch in one over.

The 39-year old Irish star still added a four under 68 to his opening 69 at Spyglass Hill to sit in a 10-man logjam for fourth place on seven under par.

“I feel like I should be a few better,” said Harrington, who birdied four of his first six holes with a brilliant putting display but missed a seven foot birdie chance at the last.

The 7th at Pebble BeachBut it’s not as if he didn’t hole his share earlier in the day. Armed with his new pre-shot putting routine, Harrington got up and down from 62 yards to save par at the first, birdied the second from 12 feet, the third from 25 feet and the fourth from eight feet.

He chipped dead to save par at the next, two putted the sixth for an easy birdie four and made up for bogey at the short seventh, where he was bunkered, by holing from 11 feet for birdie at the eighth to turn in 32.

Just three behind Marino at this stage, Harrington hit a 110 yard wedge to four feet at the 11th and holed the putt to get within two before the birdies dried up over the closing stretch.

Marino birdied the 13th, but both men then bogeyed the tricky par-five 14th, where Harrington was bunkered in three and failed to find the green with his recovery. But it was Marino who finished the stronger with birdies at the 15th, 16th and 18th.

“You know, it’s been very relaxed,” Harrington added. “I suppose playing with Steve, and he’s obviously making plenty of birdies; he’s 13-under par. And again, it’s well within him. He could holed a few more putts, made a few more birdies. So it’s easy to play good golf when you’re playing partner is playing well and you see him making birdies.”

There were light moments too, as both Marino and Harrington got caught out reminiscing about how tough the 14th hole played during the US Open last June.

STEVE MARINO: We were talking about how firm the greens were and how firm the greens were in the Open. We were talking that both of us made four pars in the U.S. Open on that hole and how we probably had like a shot and a half on the field, and then we both made a mess of it and made a bogey. We learned our lesson.

It turned out to be a classic case of thinking too much for Harrington, who was in more than two minds standing over his third and hit it heavy, plugging it in the bunker.

“I hit it heavy because I was changing my mind every few seconds,” Harrington said of the approach shot. “I probably changed my mind five or six times during that swing. … When you’re competitive, you make a decision and stick with it. When you’re coming in a bit raw, you just don’t get that commitment.”

Marino and amateur partner Dermot Desmond shot a 9-under 63 to move up to tied third on 18 under at halfway, two shots off the lead. Harrington and JP McManus posted a seven under 65 to jump to tied 48th on 10 under.