Walsh in his fourth attempt threw 20.68m defeating 2-time Olympic champion Tomas Majewski of Poland 20.44 and USA's 2007 world champion Reese Hoffa, who manged to throw 20.33m.
World Indoor Championship bronze medalist, Walsh, on Sunday at the Berlin world challenge meeting claimed 3rd place.
The main portion of the track and field competition of the Zagreb World Challenge meet continues today on September 2.
Men's Shot Put Results - IAAF World Challenge Zagreb - September 1
26 May 2022 16:00 (GMT)
26 May 2022 20:45 (GMT)
26 May 2022 21:00 (GMT)
26 May 2022 22:00 (GMT)
27 May 2022 15:00 (GMT)
27 May 2022 00:00 (GMT)
27 May 2022 00:30 (GMT)
28 May 2022 09:00 (GMT)