Alonso's 116-mph moonshot came in the third inning of the 7-4 victory Monday in Boston. The 402-foot, two-run shot left the field in 3.9 seconds as it cleared the famous 37-foot wall in left field.
"There is an advisory throughout the ballpark where you have to be aware of flying baseballs and bats," Alonso told reporters.
"Hopefully, if there was fans here they [would have] needed to not be on their cell phones and be locked into the game."
The Mets (2-2) took a 2-0 lead off a two-run homer in the top of the second frame from Michael Conforto. Alonso then stepped to the plate in the top of the next inning and doubled the lead.
The Mets first baseman settled in against Red Sox relief pitcher Jeffrey Springs during the exchange. Alonso earned a 3-0 edge in the count before he waited on Springs' fourth offering. The Red Sox left hander tossed in an 81.5-mph changeup. Alonso belted the pitch deep to left field. The home run drilled a cardboard fan after it cleared the Green Monster.
Dominic Smith broke the game wide open with a three-run home run in the next inning. Mitch Moreland nearly sparked the Red Sox to a comeback with a solo home run in the bottom of the fourth frame. Xander Bogaerts added another Red Sox homer in the bottom of the sixth inning.
Bogaerts plated J.D. Martinez in the bottom of the eighth frame to cut the Mets' lead to 7-3. Moreland returned to the plate for an RBI single in the same frame, but the Red Sox could not manufacture enough runs to close the gap over the final two innings.
Alonso went 1 for 5 with two RBIs and a run scored in the win. Conforto went 1 for 4 with two RBIs and a run scored for the Mets. Moreland went 2 for 4 with two RBIs and a run scored for the Red Sox.
Amed Rosario, Jeff McNeil and Wilson Ramos each had two hits in the victory. Mets starter Michael Wacha allowed five hits and one run in five innings to earn the win on the hill.
Alonso is now 2 for 16 with two RBIs in 2020. The 2019 National League Rookie of the Year hit .260 with 53 homers and 120 RBIs last season.
The Red Sox (1-3) host the Mets in the second game of the series at 7:30 p.m. EDT Tuesday in Boston.