"I've seen Tom in training and thrown against him a bunch of times, and he's an unbelievable competitor. Whenever I have a good throw, he seems to come back a beat me by a little bit. So he definitely made me throw my best today."
Walsh, the bronze medallist in Rio, was content with his efforts and the New Zealand residents' record, considering he struggled with timing and recorded fouls on three of his six attempts.
"Any day you throw over 21 is a good day - and Ryan Crouser had a cracking day," Walsh said. "I knew Ryan was in very good shape. So if I was allowed to bet on the competition, I would have bet on him. He was in great nick earlier in the week, so I knew I was going to have to throw high-21s to really push him."
After winning last year in Christchurch, Jacko Gill finished third with an effort of 20.69m, edging out Australian Damien Birkenhead. The transtasman pair meant the event was graced by four Olympic finalists - along with two-time world indoor champion Ryan Whiting of the United States - a level of competition that left Crouser impressed.
"You don't see many higher quality fields than what we had here today," he said. "So any time you can come down early in the year and get a good victory is always a good start."
Crouser will be looking to repeat that effort when he squares off against Walsh at the Millennium Stadium on Sunday, though the Kiwi had formulated a mid-week plan to turn the tables.
"We've got a bit of pig hunting," Walsh said. "We might just leave him in the bush in Marlborough somewhere and that will be fine."