In the 2012–13 season, Lowry regained his first team place, playing in the left-back and central defense positions until he missed one game after picking up a yellow card for the fifth time against Bristol City on 2 October 2012. After making his first team return as a left-back, Lowry then provided assist for the winning goal when he set up a goal for Chris Woods, in a 1–0 win against his former club, Leeds United on 18 November 2012. Lowry was then banned for two matches between 19 January 2013 and 25 January 2013 after picking up a yellow card for the tenth time this season. Lowry then He "curled a superb, dipping free-kick" to score from 35 yards (32 m) as Millwall beat Charlton Athletic 2–0 at The Valley on 16 March 2013. Lowry played in all matches in the run up to the Lions' FA Cup semi final against Wigan Athletic at Wembley, though he missed one match in the 4th round against his former club, Aston Villa. In late-April, Lowry was given a three match ban after being booked for the fifteenth time this season. Despite this, Lowry finished the 2012–13 season, making forty-five appearance and scoring once in all competitions.
BMW Championship: Entered the BMW Championship No. 36 in the FedExCup standings, with his T39 finish at Conway Farms outside Chicago leading to a final ranking of No. 38. Advanced to the TOUR Championship by Coca-Cola in 2012 (finished No. 28 in the FedExCup), but other three seasons led to near misses of cracking the top 30 in the FedExCup (No. 43 in 2011 and No. 32 in 2010).
In June 2015, he became the first SMU Mustang to win the NCAA individual championship, recording a score of 280 (−8) to win by one stroke. In August, he won the U.S. Amateur title, defeating Derek Bard 7 & 6 in the 36-hole final. He became the fifth player to win both the NCAA and U.S. Amateur titles in the same year, joining Jack Nicklaus (1961), Phil Mickelson (1990), Tiger Woods (1996), and Ryan Moore (2004).
PGA Championship: With his T5 finish at the PGA Championship, finishing three strokes behind champion Justin Thomas, continued to be a top-five machine in major championships, recording his seventh such finish in 32 starts. Made a furious Sunday rally, with six birdies, including four in a row on Nos 12-15, but pars on The Green Mile (Nos. 16-18) left him a few short of his friend, Justin Thomas.
Fowler is one of four golfers in the "Golf Boys" group along with fellow PGA Tour players Ben Crane, Bubba Watson and Hunter Mahan. The Golf Boys released a YouTube video of the song "Oh Oh Oh" on the eve of the 2011 U.S. Open. Farmers Insurance is donating $1,000 for every 100,000 views of the video. The charitable proceeds will support both Farmers and Ben Crane charitable initiatives.
PGA Championship: Finished T3 and two strokes behind McIlroy at the PGA Championship in his 20th major championship start, with T19 in 2013 the previous-best finish in four prior PGA Championship starts. Became the first to claim top-five finishes in all four majors since Woods in 2005. Since 1934, is just the third player to perform the feat, joining Woods in 2000 and 2005 and Jack Nicklaus in 1971 and 1973. Played all four majors in 32-under, with McIlroy second on the list, at 27-under.
5-time PGA Tour winner Bryson DeChambeau is a master of precision under pressure and one of the youngest international champions on golf’s global stage. At only 25 years old, he has already cemented his sport legacy with his innovative approach to the game. Nicknamed the “golf scientist,” DeChambeau ensures that physics are on his side. He is the only golfer on the PGA Tour with irons and wedges that measure one length, 37.5 inches, and one of the only ones who has mastered “The Science of Swing."
After finishing fifth in the Hyundai Tournament of Champions in Hawaii, Fowler claimed his first victory of 2016 in the Abu Dhabi HSBC Golf Championship on the European Tour. He shot a final round of 69 to finish one clear of Belgium's Thomas Pieters. Two weeks later, Fowler was in contention to win again but lost out to Japan's Hideki Matsuyama in a playoff at the Waste Management Phoenix Open. On March 7, Fowler sparked fantastic scenes after sinking a hole-in-one with fellow tour pro Luke Donald's pitching wedge to win $1 million for Ernie Els' charity, Els for Autism.
Nationwide Tour Players Cup: Playoff runner-up to Derek Lamely at the Nationwide Children's Hospital Invitational. Started the final round five shots behind 54-hole leader Dave Schultz. Held the lead during much of the final round but suffered a bogey at the 72nd hole of regulation to drop into a tie with Lamely and force a playoff. Lost to Lamely when he failed to get up and down from a greenside bunker on the second extra hole, missing his par putt of 12 feet. Lamely rolled in a three-foot par putt to win.
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."'
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. He had his best professional result in November 2009, when he finished 3rd in the Dunlop Phoenix Tournament in Japan. In January 2010, Lowry finished in fourth place in the Abu Dhabi Golf Championship, moving him into the top-100 of the Official World Golf Ranking.