Immediately after the Masters in mid-April 2016, DeChambeau turned professional and signed a long-term agreement with Cobra-Puma Golf.[9] He made his pro debut days later at the RBC Heritage in South Carolina and tied for fourth, earning over $259,000.[10][11] The decision to turn professional meant the forfeiture of his exemptions to the U.S. Open at Oakmont and Open Championship at Royal Troon; he qualified his way into the U.S. Open, tied for fifteenth place for over $152,000,[12] and improved his world ranking to 148.
While serving a suspension, Lowry signed a two-and-a-half-year permanent deal to Millwall for an undisclosed fee on 27 January 2012.[24] Lowry then made his first appearance for the club since joining Millwall permanently, playing 90 minutes, in a 2–1 loss against rivals' West Ham United on 4 February 2012.[25] Right way through March, Lowry was sidelined with ankle injury that kept him out for weeks.[26] After making his first team return against Cardiff City, in a 0–0 draw on 31 March 2012,[27] Lowry scored his first Millwall goal, which he scored the only goal in the game, in a 1–0 win over Coventry City on 17 March 2012.[28] Lowry finished his 2011–12 season, making twenty-two appearance and scoring once.
Waste Management Phoenix Open: Claimed his second runner-up finish at the Waste Management Phoenix Open, one shot behind Hunter Mahan. Had birdie opportunities on the last three holes but unable to catch Mahan. Previously lost in a playoff to Troy Matteson just down the road at Grayhawk GC in the 2009 Frys.com Open. Had he won at TPC Scottsdale, would have become the first Sponsor Exemption to do so since Jason Gore (2005 84 Lumber Classic). Lee Westwood later won in June as a Sponsor Exemption at the St. Jude Classic presented by Smith & Nephew.

Lowry made his professional debut in the 2009–10 UEFA Europa League in an away fixture at Rapid Vienna.[4] On 17 September 2009, Lowry signed a three-month loan deal with Football League Championship side Plymouth Argyle.[5][6] Lowry made his Plymouth Argyle debut on 19 September 2009, playing 90 minutes, in a 3–1 loss against Newcastle United.[7] He played 13 league games for Plymouth during his loan spell, where he impressed many and was recalled by Villa who required Lowry's services as cover after some injuries to defenders.[8]
Though he appeared in two matches as an un-used substitute for Aston Villa in the 2010–11 season, Lowry continued to be remain out of the first team and in January 2011, Lowry signed for Championship side Sheffield United until the end of the season[17] making his first start for the Blades away at Coventry City a day later.[18] Lowry made eighteen appearances for the Blades but with the club in decline he was unable to prevent them from being relegated at the end of the season.[14]
Though he appeared in two matches as an un-used substitute for Aston Villa in the 2010–11 season, Lowry continued to be remain out of the first team and in January 2011, Lowry signed for Championship side Sheffield United until the end of the season[17] making his first start for the Blades away at Coventry City a day later.[18] Lowry made eighteen appearances for the Blades but with the club in decline he was unable to prevent them from being relegated at the end of the season.[14]
Hyundai Tournament of Champions: Finished T6 in a Monday-start-Tuesday-finish event, the season-opening, 54-hole Hyundai Tournament of Champions. The event "started" twice during the regularly scheduled first round Friday and later Sunday, but both times PGA TOUR rules staff halted play due to unplayable windy conditions and subsequently voided all scores that had taken place. As the first player off the tee, he ended up hitting three "opening" shots of the season.
On August 26, 2018, he won The Northern Trust for his first playoff victory; in the process, he established a new record for the tournament when held at the Ridgewood Country Club, with a score of 266, besting the old Ridgewood record of 270, which was set in 2014 by Hunter Mahan.[17] The following week, he won at the Dell Technologies Championship played at TPC Boston in Norton, Massachusetts, with a final score of −16, two shots clear of Justin Rose. This put him over 2000 points ahead of the second place player, Dustin Johnson, in the FedEx Cup rankings. This margin secured him top seeding at The Tour Championship, regardless of his finish at the BMW Championship. This also marked his fourth win on tour, third for the year, and second during the playoffs.[18] At the Tour Championship, DeChambeau finished 19th out of 30 participants. As a result, he fell to 3rd in the FedEx Cup, winning $2,000,000.[19]
Lowry missed the first three cuts of his professional career, but had his first payday on 5 July, when he finished 50th at the Open de France ALSTOM.[13] He had his best professional result in November 2009, when he finished 3rd in the Dunlop Phoenix Tournament in Japan.[14] In January 2010, Lowry finished in fourth place in the Abu Dhabi Golf Championship,[15] moving him into the top-100 of the Official World Golf Ranking.[16]
Lowry elected to turn professional the week after his Irish Open triumph, meaning that he would miss out on the opportunity to play in the Walker Cup in September 2009.[11] He made his professional début on 28 May at the European Open, where he shot 78 in the first round to end the opening day almost at the back of the field, and went on to miss the cut following a second round 73.[12] 
×