Ireland's Shane Lowry will face Northern Ireland's Rory McIlroy in the first round of the WGC-Accenture Match Play Championship in Arizona on Wednesday.
With Phil Mickelson and Brandt Snedeker pulling out of the first of this season's world championships Lowry, winner of the 2009 Irish Open as an amateur, was in line to clash with second seed Tiger Woods.
But that changed when Swede Fredrik Jacobson, last man in as replacement for the injured Snedeker, finished joint third at the Northern Trust Open in Los Angeles and moved up on the world rankings from 66th into the top 50, leaving Lowry to face the world number one.
Woods will now meet his former Presidents Cup partner Charles Howell, while third seed Luke Donald - joint 16th in his first event of the year at Riviera after a disappointing closing 75 - will be up against German Marcel Siem.
McIlroy versus Lowry is not the only all-Irish duel. Graeme McDowell has to take on Padraig Harrington.
The draw also sees former winner Ian Poulter against Scotland's Stephen Gallacher and two more of the six-strong English contingent, Chris Wood and David Lynn, against Masters champion Bubba Watson and US Open champion Webb Simpson respectively.
Draw for the first round of the WGC-Accenture Match Play Championship at Dove Mountain, Tucson, Arizona, United States, on Wednesday (seeded positions in brackets):
(1) Rory McIlroy v (64) Shane Lowry, (32) Rickie Fowler v (33) Carl Pettersson, (16) Dustin Johnson v (49) Alexander Noren, (17) Graeme McDowell v (48) Padraig Harrington, (8) Bubba Watson v (57) Chris Wood, (25) Jim Furyk v (40) Ryan Moore, (9) Charl Schwartzel v (56) Russell Henley, (24) Zach Johnson v (41) Glen Day
(4) Louis Oosthuizen v (61) Richie Ramsay, (29) Branden Grace v (36) Robert Garrigus, (13) Keegan Bradley v (52) Marcus Fraser, (20) Ernie Els v (45) Fredrik Jacobson, (5) Justin Rose v (60) KJ Choi, (28) Bill Haas v (37) Nicolas Colsaerts, (12) Sergio Garcia v (53) Thongchai Jaidee, (21) Matt Kuchar v (44) Hiroyuki Fujita
(2) Tiger Woods v (63) Charles Howell, (31) Gonzalo Fernandez-Castano v (34) Francesco Molinari, (15) Webb Simpson v (50) David Lynn, (18) Peter Hanson v (47) Thomas Bjorn, (7) Lee Westwood v (58) Rafael Cabrera Bello, (26) Martin Kaymer v (39) George Coetzee, (10) Jason Dufner v (55) Richard Sterne, (23) Hunter Mahan v (42) Matteo Manassero
(3) Luke Donald v (62) Marcel Siem, (30) Paul Lawrie v (35) Scott Piercy, (14) Steve Stricker v (51) Henrik Stenson, (19) Nick Watney v (46) David Toms, (6) Adam Scott v (59) Tim Clark, (27) Jamie Donaldson v (38) Thorbjorn Olesen, (11) Ian Poulter v (54) Stephen Gallacher, (22) Bo Van Pelt v (43) John Senden