After beginning the year outside the top 250, Herbert rose steadily up the rankings. He qualified for the 2013 Paris Masters, where he defeated Benoit Paire for the loss of only four games in the first round; his first ever Tour level win of his career. In the second round, he had two set points before losing to Novak Djokovic in straight sets. He ended the year 106 places better off in the rankings.
Herbert made his Grand Slam main draw debut in 2014, first receiving a wildcard into the French Open, where he faced American number 10 seed John Isner in his opening match, losing in three tight sets. He then made it through three rounds of qualifying, beating Borna Ćorić, Daniel Kosakowski and Miloslav Mečíř, Jr. to make the main draw at Wimbledon for the first time. In the first round he faced Jack Sock, however lost in four sets despite taking the first set in a tiebreaker. Herbert got his fifth career win at Tour level at the Swiss Indoors in Basel, beating Édouard Roger-Vasselin in a tight three-setter to set up a clash with 14-time Grand Slam winner Rafael Nadal, his first meeting with a Major champion and former world number 1.
Herbert again battled through three rounds of qualifying, beating Hans Podlipnik Castillo, Facundo Argüello and Íñigo Cervantes (the latter over five sets) to make the main draw of Wimbledon. In the first round he beat Hyeon Chung in a three-hour, five-set match, winning the final set 10-8. In the second round he lost in straight sets to Bernard Tomic, the player who had beaten him in the semi-finals of Junior US Open in 2009.