Lowry made his professional debut in the 2009–10 UEFA Europa League in an away fixture at Rapid Vienna. On 17 September 2009, Lowry signed a three-month loan deal with Football League Championship side Plymouth Argyle. Lowry made his Plymouth Argyle debut on 19 September 2009, playing 90 minutes, in a 3–1 loss against Newcastle United. 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.
Presidents Cup: Closed out his second consecutive Presidents Cup appearance with a 6-and-4 victory over Emiliano Grillo, helping lead the United States to a 19-11 win over the International Team. Compiled a 3-0-1 overall record, highlighted by victories the first two days with teammate Justin Thomas in Foursomes (6 and 4 over Charl Schwartzel and Hideki Matsuyama) and Four-ball (3 and 2 over Branden Grace and Louis Oosthuizen).
With this win, he entered the Official World Golf Ranking as an amateur at No. 168 and reached a career high of sixth in the World Amateur Golf Ranking. Walker Cup captain Colin Dagleish described the win as "fairytale stuff", adding: "You'd have to say that Shane's victory was the biggest (of the three amateur wins). To win your own national Open is quite something. It was unbelievable, it really was." The win was only the second home victory since 1982 and the first since Pádraig Harrington in 2007. Harrington himself was also full of praise: "It's fabulous for Irish golf. You only have to look at the fact it is such a rarity for an amateur to win, such a rarity for an Irish player to win the Irish Open. So, on a lot of fronts, it is a big deal. It was very impressive."
the Memorial Tournament presented by Nationwide: Erased a five-stroke deficit in the final round and briefly held the lead before eventually shooting a final-round 70 to finish runner-up in the Memorial Tournament, three shots behind Jason Dufner. Hit a 350-yard drive on the 72nd hole and had just 136 yards to the pin when play was called for inclement weather for the second time during the final round. When play restarted, he made a costly bogey at the last to fall into a tie for second. Ranked No. 1 in fairways hit for the week with 45 of 56. Was also 8 of 11 in sand saves to rank first for the week.
All of DeChambeau's irons and wedges are cut to exactly the same length: 37.5 inches (95.3 cm). Their lie and bounce angle are also the same; only the lofts are different. In addition to the single-length concept, his clubs are unusual for their extremely upright lie angle.  DeChambeau keeps the club on the same plane throughout his swing and does not turn his wrists during his swing. In 2011, at the suggestion of his instructor Mike Schy, DeChambeau switched to JumboMax Grips, the largest grips commercially available. The larger grips allow DeChambeau to hold the grips in his palms and not his fingers.
On 28 January 2010, Lowry agreed a deal which would take him on a loan to Leeds United until 13 March 2010, joining his fellow Australian international teammates Patrick Kisnorbo and Neil Kilkenny. He made his debut for Leeds against Colchester United, playing left back for Leeds. After an impressive debut, Lowry suffered a minor injury and had to be substituted and replaced by Bradley Johnson after 70 minutes. After missing the FA Cup replay against Tottenham Hotspur due to not being eligible, Lowry returned to the Leeds starting lineup in the following game against Hartlepool United.
The Barclays: Held a one-stroke lead over Patrick Reed after 54 holes at The Barclays in the FedExCup Playoffs, before a double bogey-birdie-bogey finish on Nos. 16-18 resulted in a T7 at 6-under 278 with Jason Kokrak and Ryan Moore. Fowler went bogey free at Bethpage Black from the 10th hole in round one until the 11th hole in the final round, a span of 55 holes. His 55-consecutive holes without a bogey became a personal best on the PGA TOUR, besting 53 from the 2010 Memorial Tournament. This streak also marked the longest recorded in Barclays history since hole information began in 1983. Ian Poulter had the longest with 45 in 2010. The finish marked his third top-10 showing in his last four starts in the event (T9/2013, T9/2014).