Spieth loses match and No. 1 ranking at Match Play

Rory McIlroy, of Northern Ireland, chips onto the sixth green during the round of 16 play against Dustin Johnson at the Dell Match Play Championship golf tournament at Austin County Club Saturday, March 26, 2016, in Austin, Texas. (AP Photo/Charlie Riedel)

AUSTIN, Texas (AP) Jordan Spieth lost in the fourth round at the Dell Match Play. Then, he lost his No. 1 ranking.

Jason Day assured a return to the top of the ranking when he beat Brooks Koepka to advance to the semifinals. Next up for Day is Rory McIlroy, who overwhelmed Chris Kirk on the back nine at Austin Country Club to run his unbeaten streak in this tournament to 12.

The other semifinal match was still to be determined.

Louis Oosthuizen took the lead on the fourth hole and never trailed against Spieth.

Day and McIlroy have never met in match play. McIlroy is trying to join Tiger Woods as the only back-to-back winners of this event.