Question: What mid-fifties Canadian golf event on the PGA Tour was sponsored by the largest brewer in Canada?

Context paragraphs:
SiriusXM PGA Tour Radio: SirusXM PGA Tour Radio is Sirius XM Radio's Golf channel, located on XM channel 92, Sirius channel 208.  The channel provides comprehensive play by play coverage of all 4 majors including The Masters, U.S. Open, The Open, & the PGA Championship, as well as the Ryder Cup, Presidents Cup, and over 40 PGA TOUR events every year.  The Talk programming covers news from the PGA Tour, the LPGA, PGA TOUR Champions, European Tour and Web.com Tour, in addition to shows focused on instruction, fitness, college golf, club fitting, and any other subject in the game of golf.  Hosts on the channel include PGA TOUR Pro Pat Perez, Ben Crenshaw, Craig Stadler, Chris DiMarco, Larry Mize, Hale Irwin, Mark Calcavecchia, Dave Stockton, Instructors Hank Haney, David Leadbetter, Jim McLean, Musician Darius Rucker and many more.  Following the Sirius / XM merger, the PGA Tour Network was added to Sirius on September 30, 2008 as part of its Premier package and broadcasts on channel 208.

Middle Atlantic PGA Championship: The Middle Atlantic PGA Championship is a golf tournament that is the championship of the Middle Atlantic section of the PGA of America.  The tournament has been played annually since 1932 in Virginia, Maryland, or Washington, DC.  Fred Funk, eight-time winner on the PGA Tour, holds the record with six Middle Atlantic PGA victories.  Other PGA Tour winners who have also won the Middle Atlantic PGA Championship include Chandler Harper (seven time PGA tour winner and 1950 PGA Championship winner), Bobby Cruickshank (17-time PGA tour winner), Lew Worsham (four-time PGA tour winner), and George Fazio (two-time PGA tour winner and golf course designer).

Northern California PGA Championship: The Northern California PGA Championship is a golf tournament that is the championship of the Northern California section of the PGA of America.  Mark Fry, long-time pro at Sequoyah Country Club in Oakland, California, holds the record for most victories with 10.  Tony Lema, British Open winner in 1964 and 12-time PGA Tour winner, won three consecutive Northern California PGA championships from 1962–64.  Other PGA Tour winners who were also victorious in the Northern California PGA Championship include Bob Lunn (six-time PGA tour winner), Dick Lotz (three-time PGA tour winner), Bruce Summerhays (three-time PGA tour winner, Bob Wynn, and John McMullin.

PGA Tour: The PGA Tour (stylized in all capital letters as PGA TOUR by its officials) is the organizer of the main professional golf tours played primarily by men in the United States and North America.  It organizes most of the events on the flagship annual series of tournaments also known as the PGA Tour, as well as PGA Tour Champions (for golfers age 50 and older) and the Web.com Tour (for professional players who have not yet qualified to play in the PGA Tour), as well as PGA Tour Canada, PGA Tour Latinoamérica, and PGA Tour China.  It is headquartered in Ponte Vedra Beach, Florida, a suburb of Jacksonville.

2013 PGA Tour Canada: The 2013 PGA Tour Canada season runs from June 6 to September 15 and consists of nine official golf tournaments.  This is the 44th season of PGA Tour Canada (previously known as the Canadian Professional Golf Tour), and the first under the "PGA Tour Canada" name.  On October 18, 2012, the Canadian Tour and the U.S. PGA Tour announced that they had reached an agreement by which the PGA Tour would take over the Canadian circuit.

Stan Leonard: Stan Leonard (February 2, 1915 – December 15, 2005) was a Canadian professional golfer who played on the PGA Tour in the 1950s and 1960s.  Leonard won three PGA Tour events, eight Canadian PGA Championships, and 16 other events on the Canadian Tour.  He is a member of the Canadian Golf Hall of Fame.

2017 PGA Tour Canada: The 2017 PGA Tour Canada season ran from June 1 to September 17 and consisted of 12 official golf tournaments.  This was the 48th season of PGA Tour Canada (previously known as the Canadian Professional Golf Tour), and the fifth under the "PGA Tour Canada" name.  It was also the third under the Mackenzie Tour – PGA Tour Canada name after Mackenzie Investments signed a six-year sponsorship deal.

Labatt Brewing Company: Labatt Brewing Company Ltd. (French: "Brasseries Labatt du Canada Ltée" ) is a Belgian-owned Canadian beer company founded by John Kinder Labatt in 1847 in London, Ontario.  Labatt is the largest brewer in Canada.

PGA Assistant Championship: The PGA Assistant Championship is a golf tournament for golf club assistant professionals.  It has been held by the PGA of America since 1977.  Rules for 2007 have the field made up of the assistant champions from each PGA section, section qualifiers, the defending champion and a representative from the PGA of Australia, The Professional Golfers' Association and the Canadian PGA.  The 2015 Champion was Andy Mickelson.  Notable players who won this event before competing on the PGA Tour include Loren Roberts (eight PGA Tour wins), Fred Funk (eight PGA Tour wins), and Wes Short, Jr. (one PGA Tour win)

Labatt Open: The Labatt Open was a golf event on the PGA Tour that was played in Canada in the mid-1950s.  It was sponsored by the Labatt Brewing Company.  It was played at several different courses.

Supporting paragraphs: Labatt Open Labatt Brewing Company
Answer: Labatt Brewing Company