While Haas got around the course in his usual busy fashion, arriving at his ball, being given a yardage by his caddie, pulling a club, then firing at the target, Na dithered and dallied, checking the wind, checking the yardage, checking his swing and finally, after what seemed much longer than the 40 seconds allocated to him under competition rules, pulling the trigger.
It was so tedious watching Na go through this routine that you wondered why PGA Tour officials havenâ€™t at some stage slapped him with a slow-play penalty. How can being subjected to this torture help to expand golfâ€™s dwindling fan base? If anything, it must have had non-committed viewers reaching in droves for their TV remotes.
Little wonder that Adam Scottâ€™s caddie Steve Williams blew a gasket three years ago when Scott was playing alongside Na during the 2014 Deutsche Bank Championship at TPC Boston.
As Sports Illustratedâ€™s Alan Shipnuck tells it, Williams was apparently incensed by the Americanâ€™s glacial pace of play over the first two rounds, and refused to shake Naâ€™s hand after the first day.
"In the scoring tent," Na told Shipnuck, "as I was about to leave, Stevie looks at me and goes, 'Do you ever watch a bad movie again and again?' I didn't really know what he was talking about, so I just said, 'Uh, no.' He goes, 'That's what you are, Kevin, a bad movie. I never want to see you play againâ€™.â€ť
Things then got quite heated before one of the Tour officials stepped in and separated the pair.
Last week, Sports Illustrated and golf.com released the results of a poll of 50 tour players who were asked their thoughts on a range of topics relating to the tour. One of them, of course, concerned the pace of play.
Eighteen per cent of those polled named American journeyman Matt Every as the fastest player on Tour, with Australiaâ€™s Matt Jones coming in next with 14 per cent of the vote, then Haas third on 8 per cent.
As for the tour tortoises, five-time PGA Tour winner Ben Crane was named by his peers as the slowest player, receiving 21 per cent of the vote, closely followed by Na on 17 per cent. (Jason Day, it should be noted, was third on the list with 11 per cent).
This was why the Na-Haas face-off was such compelling viewing on Saturday: Haasâ€™ quick-fire routine only accentuated Naâ€™s mind-numbing approach â€“ and brought into sharp focus this issue which is threatening to undermine every effort to attract more people to the game.
In response to another question in the Sports Illustrated and golf.com joint poll, 84 per cent of players said slow play was a problem on the PGA Tour, with 40 per cent saying they would support the idea of a "shot clock", much like in basketball.
Yet the PGA Tour and European Tour seem to be curiously reticent to make a stand.
Given that heâ€™s just taken over from Tim Finchem, you might imagine new PGA Tour Commissioner Jay Monahan would want to make his mark on the job but he said recently he sees no need to expedite the pace of play.
All quiet on the European Tour front, as well, where after an initial flurry of statements on the topic, Keith Pelley has apparently gone into hibernation.
Maybe golfâ€™s officials were taken aback by the reaction to their decision to dock Chinese schoolboy Guan Tianlang one shot for slow play on his Masters debut in 2013.
Only 14 years old at the time and the youngest player to ever tee up at the Masters, Tianlang was the first to be penalised at the yearâ€™s first major - which seems difficult to fathom considering how many notorious slow coaches have trod the fairways at Augusta National.
At the time, Ben Crenshaw, Guanâ€™s playing partner over the first 36 holes, said: â€śI'm sick for him. I feel terrible. He is 14 years old. I'm so sorry this has happened.â€ť
For the record, the PGA Tour rules for pace of play includes the 40-second time limit, but also allows an extra 20 seconds (for a total of 60 seconds) under the following circumstances:
*The first player to play a stroke on a par-3 hole
* The first player to play a second stroke on a par-4 or par-5 hole
* The first player to play a third stroke on a par-5 hole
* The first player to play around the putting green
* The first player to play on a putting green
Slow play can, in theory, lead to penalty strokes or disqualification. Yet in practice, the PGA Tour almost never hands out penalty strokes for slow play. In fact, the most recent stroke penalty for dawdling (apart from the Guan Tianling incident) came about in 1995, and the recipient was Glen Day.
So it doesnâ€™t exactly sound like the gameâ€™s ruling bodies are united in a full-on assault against this modern-day scourge.
Society is changing, other sports are introducing new, easily digestible formats, and yet golf is sitting on its hands and letting this problem go unchallenged.
As one obviously frustrated tour player said in response to the SI/golf.com question about what should be done to speed up play: "How about we enforce something sometime? And not on a [14-year-old] kid at the Masters. What a joke!"
DENNISE HUTTON DEMONSTRATES THE COIL DRILL
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