The play-off had gone to a fourth hole after players on both sides fluffed chances to win on the opening three holes of sudden death.
First Masters to be decided in play-off since 2013.
Spieth soars into contention with a fine four-under 68.
Defending champion Willett, Watson and Stenson miss cut
The American journeyman leads on seven under par
The world No.1 injured his back after falling from staircase in his Augusta rental home.
QATAR’S Saleh Al Kaabi continued his impressive form as he won the 54th Bahrain Open at the Awali Golf Club last week.
The talented trio of Erick Moss, Raza Mekhary and Vinoth Irjay emerged as winners with a score of 56.0 at the American Chamber of Commerce in Qatar’s (AmCham Qatar) Seventh Golf Tournament last week.
The course will now be eligible to host Britain's Open
QATAR won team bronze at the Third GCC Women’s Championship in Manama last week. The duo of Yasmian Al Sharshani and Maryam Al Sada had a gross score of 682 (240, 243, 199) in the three-day event held at the Royal Golf Club.
The American had been third in the world rankings before leapfrogging the Australian Day.
The Spaniard played a bogey-free round of three-under-par 69 to finish on 19-under-par 269 to win the oldest professional tournament in the Middle East.
The Spaniard shot a four-under par 68 at the Emirates Golf Club and goes into the final day of the $2.5m European Tour event at 16-under par 200.