He might have missed four putts inside five feet but Shane Lowry was still beaming after knocking in a 12 footer for par at the last to give himself an outside chance of victory in the Waste Management Phoenix Open.

The 29-year old admitted he'd have been frustrated to bogey the last having played brilliantly for most of the day and left himself just 120 yards to the pin from the middle of the fairway.

On a day when he missed three birdie putts inside five feet having enjoyed another majestic ball-striking day, the pride of Clara misjudged his approach to the 18th and hit an average pitch before rolling home the putt for a five under 66 that left him tied 12th on 10 under par.

Yes, he's, six shots behind Byeong Hun An of South Korea. But if he can bring his putter up to the same temperature as the rest of his game — he's in the top 10 for every ball striking statistic but 61st for putting after taking 32, 31 and 30 putts — he's capable of producing some serious Sunday fireworks.

"It was good — the best I've played in a long time," said Lowry, who opened up with all guns blazing by making birdies at his first four holes.

His putter was clearly working early on as he followed a 17 footer at the first with a pair of three and a half footers and an 11 footer following some stellar drives and rapier-like irons shots.

When he made an 18 footer for his fifth birdie of the day at the eighth, he had the leaders in his sights. But he lost his way a little with the blade coming home and followed a bogey at the ninth by missing from inside three for par at the 11th.

A three-putt there wasn't ideal and while he made a nice six-footer for par at the 12th and an eight-footer for birdie at the par-five 13th, he missed a four and a half footer for birdie at the par-five 15th and a five-footer for birdie at the 129-yard 16th  before saving that par at the last.

"I feel like I should have been a lot better. I think I missed four putts inside four feet and three of them were for birdie. So it was one of those days where I am really happy with my score and I think I have a chance going into tomorrow. 

"It could have been better but I did hole about a 12 footer on the last for a par which was really nice. I had only 120 yards to the flag with my second shot from the middle of the fairway and had a 12-footer for par. So it would have been a bit annoying not to make par there but I am pretty happy."

Lowry loves a stage and he's a big fan of the Phoenix event with its party atmosphere at the stadium-like, par-three 16th

"It's great," he told Sky Sports. "To be honest, I would mind seeing golf go like this all the time.  I think it is just amazing. There is a great buzz around the place all the time. Sixteen is just crazy. It is one of those holes you need to play a few times in the tournament to actually get used to it. I've loved every minute of it this week and I am looking forward to tomorrow."

Lowry got into the spirit of things at the 16th by handing out cans of Guinness to the fans in the stands.

Leader An carded a bogey-free, six under 65 to lead by a shot from Scotland's Martin Laird (65) on 16 under par after a day of perfect, windless conditions at TPC Scottsdale.

Lowry is one of 19 players within seven shots of the lead and having finished tied sixth on his debut in Phoenix last year, he's confident he can put in a fast finish.

He has two more events to play before he takes a month off to be at home with his wife Wendy, who is due to give birth to the couple's first child in three weeks. 

"I am playing the next two weeks, so I am hoping she doesn't come early," Lowry beamed. "I am taking a month off when Wendy has the baby and I am going to come back for the Match Play and play Match Play-Masters. 

"I am looking forward to it. Wendy is at home now and she is almost ready to go. We are both looking forward to it and very excited."