'I went out and I played, as far as I could tell, probably the best round of golf I've ever played under any conditions, any pressure situation, anything,' said Beem. 'I hit the ball, with the exception of a couple tee shots - I don't know if I missed any greens. I can't think of one.
'But yeah, watching Steve have the opportunity to win was certainly one of the most stressful times of my life. But that's the way this format goes.'
With his father in attendance to lend support, Beem took control midway through the front nine and never let up on the field, finishing on top with a four-day total of 44 points.
But it was Lowery who had thoughts of his own coming down the stretch.
Lowery, who started the day just one back, had three birdies on the front but also surrendered three bogeys to fall off the pace. But with a beautiful save from the greenside pond on the par-5 14th to make birdie, and an unbelievable holed iron shot from the fairway on the par-4 15th, the lead was somehow three.
Beem then responded by rolling in yet another putt, this time for an eagle 3 on the par-5 17th to put to rest any doubt.
But Lowery was not yet done.
Standing in the faiway on the par-5 17th, playing in the final group, Lowery let fly a prayer that on this day was destined to be answered.
And indeed it was, for double eagle and an almost unheard of eight points, to close the lead to a mere point going to the 18th.
'I've never made double-eagle,' Lowery said. 'This is the first time. Yeah, shocked. The crowd's reaction, you could tell that it's close or when it goes in, you could tell and after I saw it go in on 14, you kind of get the idea of what they are going to do.
'You know, I didn't know the leaderboard. The last leaderboard I saw was Rich Beem was 39. And I'm doing my math, thinking I'm 43 and thinking he birdied 17, at least, so I'm thinking he's probably 41 until I actually got up there and realized he made eagle. So then I had to regroup a little bit and tried to birdie the last hole.'
With Beem looking on in shock of what was unfolding before him, Lowery again knocked a 7-iron to 12 feet to set up a birdie try and two points, and ultimately an improbable victory.
But the putt drifted just wide and the emotional Beem was left standing as the champion.
Lowery, who tallied an amazing 14 points on the four-hole stretch from 14 through 17 to set up the wild finish, had a four-day total of 43.
'I just looked him in the eye and I was just smiling' said Beem. 'He was, too. I'm like, it doesn't get any better than that, does it? That was great playing. He congratulated me on the same thing. It was wild.'
Beem himself scored the second most points ever in a day with 19, which included seven birdies and the eagle on 17.
Mark Brooks, who was two off the pace to start the day, had troubles early but had a couple of birdies and an eagle on the back nine to come in third with 33 points.
British Open champion Ernie Els had another solid if not spectacular round, carding five birdies and landed in fouth place with the suprising Greg Norman.
Norman, who won the inaugural event here in 1986, started strong and got to within four of the lead, with birdies on five of his first eight holes. But a double bogey on the 12th left him out of the drama-filled ending. He and Els had 27 points apiece.
Lee Janzen, who had a quiet but productive first three days, came to life carding birdies on Nos. 1, 4, 7 and 8 to get onto the leaderboard. A few more on the back side gave him 26 points and fifth place all alone.
Overnight leader Craig Barlow took minus-3 point double bogeys on the fourth and fifth holes to drop out of contention and came in a tie for seventh.
Sergio Garcia could not get things going on Sunday after a his awesome display of 19 points on Saturday. Four straight bogeys on the front side removed any chances he may have had to catch the leaders. He had minus-2 points on Sunday and finished in 18th place.
Tom Lehman had another solid day that saw him get into the top 10 with a second consecutive day of 11 points. He had six birdies to go with a lone bogey and finished with 23 points.
With the victory Beem earns automatic entry into the PGA Championship at Hazeltine in two weeks.
He most certainly deserves it.
Full-field scores from The International