Lowry received his first call-up to the full Australia squad for a friendly against the Netherlands in Sydney and the Asian Cup qualifier against Oman in Melbourne in October. He did not play in either match. On 11 May 2010 he was selected as part of Pim Verbeek's 30-man provisional squad for the 2010 World Cup, and travelled to South Africa, but was not included in the final 23-man World Cup squad. Lowry was named in Han Berger's 18-man squad for an August 2010 friendly against Slovenia, but he did not appear in the match.
On 23 November 2011, Lowry was again loaned out to play in the Championship, this time to Millwall until 3 January 2012. He followed Aston Villa team-mate Nathan Baker who also signed on loan for Millwall two days earlier. Lowry made his Millwall debut three days later, where he played 90 minutes, in a 0–0 draw against Crystal Palace. His impressive display at Millwall soon earned a loan extension. Weeks later on 13 January 2012, Lowry was sent-off in the 22nd minutes after stamping on Nikola Žigić, which saw Millwall lose 6–0. Three years on after signing for Birmingham City, Lowry stated, quoting: "Whatever club I play for I fully commit to that club at the time. I play with my heart on my sleeve. Sometimes in the past I have gone overboard but I was a younger player then, I have learned a lot from these types of experiences. But I am an aggressive player, that’s the way I like to play and I can’t change the way I play. I will use my experience now and be a bit more clever."'
At the 2016 U.S. Open at Oakmont Country Club near Pittsburgh, Lowry shot 65 (−5) in the third round for 203 (−7) and a four-stroke advantage over Dustin Johnson and Andrew Landry at the 54-hole stage. The 65 was Lowry's joint career best round at a major championship. Due to weather delays on Thursday, the third round was not completed until early on Sunday, and Lowry birdied two of his remaining four holes to extend his two stroke overnight lead to four. In the final round he was in contention for the title, within one shot of Dustin Johnson after 12 holes, before three consecutive bogeys on holes 14, 15 and 16 ended his chances. He finished the tournament tied for second place, with a final round score of 76.
Lowry won for the first time as a professional in 2012, at the Portugal Masters in October. He shot a 67 to tie for the lead with the Englishman Ross Fisher, who made bogey on the final hole after missing a four-foot putt. The victory lifted Lowry back into the Official World Golf Ranking top 100 and made him eligible to compete in the WGC-HSBC Champions.
Lowry made his Leyton Orient debut, playing as a left-back position, in the opening game of the season, which saw Leyton Orient lost 2–1 to Chesterfield. Since his debut, Lowry established himself in the left-back position in the first half of the season despite being sidelined with suspension and fitness concern that saw him out for two matches. Following his return to the first team, Lowry played in the central-defense between December and March until he dropped from the first team throughout March. Lowry went on to make his first team return throughout 2014–15 season, making thirty-four appearance in his first season at Leyton Orient.
Wells Fargo Championship: Made birdie-3 on the first extra hole (No. 18) to defeat Rory McIlroy and D.A. Points at the Wells Fargo Championship for his first TOUR win. Improved to 1-1 in playoffs (lost to Troy Matteson, 2009 Frys.com Open). The playoff was the fifth at the Wells Fargo Championship. At the age of 23 years, 4 months, 23 days, became the third player to make the Wells Fargo Championship his first PGA TOUR win (Anthony Kim in 2008 and McIlroy in 2010). Became the third-youngest winner of the event, behind McIlroy (20 years, 11 months, 28 days) and Kim (22, 10, 15). His win came in his 72nd start on TOUR and was his 16th top-10 finish. Opening-round 66 is the lowest start by a winner of the Wells Fargo Championship. Won in his third start at the Wells Fargo Championship (T6 in 2010 and T16 in 2011).
NASSAU, Bahamas — Bryson DeChambeau is the same height as Tiger Woods, but as the two stood on the Albany driving range Monday afternoon, there was no question who was larger. Woods is famous for his love of working out, but these days he’s dwarfed by DeChambeau, who has directed the full force of his obsessive nature towards the gym. This is Bryson’s Bulking Season, and it’s starting to show.