Kevin Na drew a line in the sand, and ultimately that proved to be the best recipe for success at the Charles Schwab Challenge. Here's how things ended at Colonial, where Na won by four shots for his second win in less than a year:

Leaderboard: Kevin Na (-13), Tony Finau (-9), Andrew Putnam (-8), C.T. Pan (-8), Jonas Blixt (-7)

What it means: Na started the final round with a two-shot lead, and he estimated after the third round that he needed to reach 12 under to put the tournament away. That prediction proved prophetic, as Na walked up the final fairway at 12 under with a victory assured before adding a final birdie putt for a little extra style. It's the third career victory for Na, but his second in less than a year after halting a lengthy victory drought last summer at The Greenbrier.

Round of the day: Na rocketed up the leaderboard with an 8-under 62 in the second round, but it was a clinical dissection of a historic venue Sunday that made the difference. Na made six birdies against two bogeys en route to a 4-under 66, widening his lead with four birdies over his first seven holes to signal to the other contenders that he had no plans to come back to the field.

Best of the rest: Putnam got his first career victory last summer in Reno, and he added another top finish with a closing 66 that gave him the clubhouse lead at one point. Putnam got off to a hot start, playing his first seven holes in 4 under, and added two more birdies coming home to notch his best result since a runner-up at the Sony Open in January.

Biggest disappointment: The putting magic ran out for Jordan Spieth. After riding a historic hot streak on the greens en route to a tie for second through three rounds, Spieth nearly went birdie-free before rolling in a 15-footer on the final green. Spieth shot a 2-over 72 that dropped him into a tie for eighth, eight shots behind Na's winning total, as his search for his first win since the 2017 Open continues.

Shot of the day: The Horrible Horseshoe of Nos. 3-5 has derailed many rounds at Colonial, but Na played it in under par thanks to a 32-foot make on the par-3 fourth. After stuffing a wedge on his second hole, Na made the lengthy putt to reach 2 under on his round and put a little distance between himself and the other players trying to chase him down.

Quote of the day: "When I was standing on the first tee, I looked at that wall and in my head I engraved my name on it." Na, who now joins the wall of champions that sits next to the first tee at Colonial.