The Cardinals prospect allowed one run on one hit -- a solo homer -- over six innings Wednesday as Class A Advanced Palm Beach rallied for a 3-1 victory over St. Lucie.
Watson set down the side in order in the first inning, but Mets' No. 6 prospect Wilmer Flores homered to left field leading off the second.
It was the first longball allowed by the 22-year-old since turning pro. And it was Flores' 10th of the season and eighth off right-handed pitching.
Richard Lucas drew a two-out walk, but he was the final Met to reach base against Watson, who retired the last 13 batters he faced and finished with four strikeouts.
Selected in the 37th round of last year's Draft out of Wartburg College in Iowa, Watson made 11 Gulf Coast League appearances, including eight starts, in his first pro season. He went 5-1, ranked fourth in the Rookie-level circuit with a 2.22 ERA and struck out 37 while walking only five over 48 2/3 innings.
Watson led all Cardinals Minor Leaguers with a 7.40 strikeout-to-walk ratio and ranked third with a 1.15 WHIP.
Palm Beach trailed, 1-0, when Watson exited, but Jonathan Rodriguez smacked a three-run homer in the seventh to make a winner of Aidan Lucas (1-0). The 24-year-old righty walked one over two hitless innings and Chase Reid pitched around a two-out hit in the ninth for his third save of the season.
Mets starter Chase Huchingson (5-4) was charged with two runs on four hits over 6 1/3 innings, walking two and fanning seven.