He received a similar reaction on social media, where even some of the Giants' biggest rivals tipped their caps:
— Colorado Rockies (@Rockies) September 30, 2017
Congratulations to Matt Cain, who announced his retirement earlier today, on a decorated career. Best of luck in all your future endeavors! pic.twitter.com/kG9UUBB7k8
— Arizona Diamondbacks (@Dbacks) September 27, 2017
Easy for them to say, as they never have to face "The Horse" again. Cain beat the Colorado Rockies 17 times and the Arizona Diamondbacks 15 times, easily more than his third-most victimized team (eight wins vs. the San Diego Padres).
Among the others to congratulate Cain were actor and noted Giants' fan Colin Hanks and a swath of former and current teammates:
— Colin Hanks (@ColinHanks) September 30, 2017
Cainer, thanks for everything you've given this team and San Francisco. Truly an honor to be your teammate. pic.twitter.com/ogUVPXKGzr
— Hunter Pence (@hunterpence) October 1, 2017
You did it right! You ended your epic career with an epic start! You're "shotgun" Cain", and always will be the "the horse" pic.twitter.com/5NgeKNkjhO
— Jeremy Affeldt (@JeremyAffeldt) September 30, 2017
— Mark Melancon (@Mark_Melancon_) September 30, 2017
One of the BEST pitchers I've ever caught and a GREAT friend,3x🏆CONGRATULATIONS on retirement to the horse,Matt Cain!🙏🏽 Enjoy your next chapter with your family!!
-The Molinas!! @SFGiants pic.twitter.com/zKzqzuywf7
— Bengie Molina (@BengieMolina1) September 29, 2017
— San Francisco Giants (@SFGiants) September 30, 2017
— Connecticut Tigers (@thecttigers) September 30, 2017
— Lou Seal (@LouSeal01) September 30, 2017
Today one of this games greatest, but even more, one of the coolest, most down to earth guy that I've ever met announced his retirement. Cainer, it has been an absolute pleasure and honor to play this game beside you! Thankyou for welcoming me in as one of y'all and for always leading by example. Our friendship is something I will always cherish and I hope that this next chapter in your life treats you as well as this last. Best wishes brother! @sfgiants
— Make-A-Wish America (@MakeAWish) September 30, 2017
What a career for Matt Cain. One of my favorite pitchers to ever watch during my career. Incredible competitor. Awesome guy. Congrats, Matt!
— Brad Ziegler (@BradZiegler) September 28, 2017
— Nicole Vogelsong (@nicolevogelsong) September 28, 2017
Congratulations Cainer on having a career that everyone dreams of having and so few are fortunate enough to achieve! Cainer was the first person I met as I walked into the Giants clubhouse for the first time in 2012; 3 days later he pitched the first #PerfectGame in franchise history. I'm honored to have been a friend and teammate with you for so many years and now I look forward to having long drive competitions on the course! Cheers my brother, to an amazing career and to everything that comes next! #ForeverGiant #Horse #18
Cainer was the best teammate, toughest teammate, and most heavy handed teammate! TY for taking your bow, you earned everything @SFGiants
— Kevin Frandsen (@KevinFrandsen) September 30, 2017
Matt Cain is a guy who did it right. What a great career and sendoff for him.
— Brett Anderson (@BAnderson3737) September 30, 2017
Hell yeah Cainer! Hats off to an incredible career! It's been an honor to put on the same jersey as you the past year and half. Congrats!!
— Will Smith (@White_Willy13) September 30, 2017
Congrats to one of the all-time great Giants Matt Cain! A career most only dream of. It was an honor to play and learn from you! #TheHorse
— Chris Stratton (@cstratton34) October 1, 2017
Thank you for teaching me how to be a professional Cainer. Great player but an even better person.
— Christian Arroyo (@arroyo_c) September 28, 2017
Playing defense today behind Matt Cain was one of the most memorable chapters in my career. Great competitor, even better person! #TheHorse
— Ryder Jones (@Jonesy_56) October 1, 2017
Cain, who turns 33 tomorrow, finishes his Giants career having made 331 starts, sixth-most in franchise history.