Kuchar was ranked ninth last week and then posted four steady rounds en route to his Memorial victory Sunday. It was his second PGA Tour win of the year (he also won the Accenture Match Play in February).
The Top 10 players in the rankings didn't have a great showing last week, considering the U.S. Open in Ardmore, Pa., is on the horizon. Only Justin Rose, who drops to fifth this week, and third-ranked Adam Scott finished in the Top 20 at Muirfield. Rose tied for eighth and Scott tied for 13th.
No. 1-ranked Tigers Woods had four rounds in the 70s, including a 79 Saturday, and wound up tied for 65th. Second-ranked Rory McIlroy tied for 57th.
Mikko Ilonen, picking up his first European Tour win in six years, won the Nordea Masters in Sweden, improving his ranking 45 places to No. 69.
The Top 10, with rankings points average:
1. Tiger Woods, 13.27
2. Rory McIlroy, 9.85
3. Adam Scott, 7.69
4. Matt Kuchar, 6.78
5. Justin Rose, 6.48
6. Brandt Snedeker, 6.13
7. Luke Donald, 6.03
8. Graeme McDowell, 5.74
9. Louis Oosthuizen, 5.47
10. Phil Mickelson, 5.09