Lewis won the
World Masters and
WDF World Cup boys' events in 2009. Lewis reached the last 24 of the
2010 World Masters, losing 2–3 in sets to
Ted Hankey. He also reached the semi-finals of the
2011 WDF World Cup, losing out to
Martin Adams 3–6. In January 2012, then-20-year-old Lewis successfully earned a
Professional Darts Corporation tour card on day four of the
PDC Pro Tour Q School. This enabled him to participate in all 2012 and 2013 Players Championships, UK Open Qualifiers and European Tour events. Lewis competed in his first
UK Open in
2012, defeating
Steve Farmer and
Mark Stephenson before falling to
Pete Hudson in the second round. In August, Lewis beat John Scott and Michael Barnard in the UK Qualifier for the fourth European Tour event of the year, the
German Darts Masters, but then lost 3–6 to
Richie Burnett in the first round in
Stuttgart, Germany. He also still competed, and won twice, on the 2012 Youth Tour. Lewis finished fourth on the 2012 Youth Tour Order of Merit, but was the highest player who had not already qualified for the
2013 World Championship. In Lewis' first appearance in the tournament he lost to the Philippines
Lourence Ilagan in the preliminary round by four legs to three, despite leading 3–1. He was ranked world number 68 after the event. At the
UK Open, Lewis lost 5–3 to
Tony West in the preliminary round. Lewis reached his first final on the main tour at the
Gibraltar Darts Trophy. He beat
Colin Osborne 6–4,
Robert Thornton 6–5,
Steve Brown 6–0,
Kevin Painter 6–5 and two-time world champion
Adrian Lewis 6–5. His match against Lewis guaranteed him a spot in the
World Matchplay for the first time and Lewis stated that that match was his final. In the final itself he was defeated 6–1 by 16-time world champion
Phil Taylor. He played Painter in the first round of the World Matchplay and was defeated 10–7. His best results in the rest of the year were in two
Players Championships where he lost in the quarter-finals to
Mensur Suljović and Jamie Robinson. His performances over the year saw him finish 32nd on the
ProTour Order of Merit to claim the final spot in the
Players Championship Finals. In Lewis' debut in the event he faced top seed
Michael van Gerwen in the first round and lost 6–1.
2014 His ProTour ranking saw him qualify for the
2014 World Championship by claiming the third of sixteen spots that were available to players outside the top 32 on the main Order of Merit. Lewis played
Raymond van Barneveld in the first round and was beaten 3–0, losing each set by three legs to one as he hit only three of his fourteen darts at a double. Lewis had risen 28 places during the year to be ranked world number 40. In February 2014, Lewis reached the second Pro Tour final of his career by averaging 108.07 in defeating world number one
Michael van Gerwen 6–4 in the semi-finals of the fourth
UK Open Qualifier, but he could not replicate the performance in the final as he was beaten 6–1 by
Brendan Dolan. He advanced to the fifth round of the
UK Open for the first time a month later but was beaten 9–5 by
Mensur Suljović. During the rest of the campaign, Lewis was beaten in the last 16 of three
Players Championships and qualified for three European Tour events, but could not get past the second round.
2015 Lewis had taken out finishes of 141 and 125 to be level at 1–1 against
James Wade in the first round of the
2015 World Championship. He won the first leg of the third set, but then lost six legs in a row to be knocked out 3–1. His first semi-final appearance in over a year came at the
2015 Gibraltar Darts Trophy where he was beaten by
Michael van Gerwen 6–1. Lewis made his
PDC World Cup of Darts debut as the-then number two Welsh player on the Order of Merit behind
Mark Webster and they teamed up at the
2015 event, but suffered a surprise 5–3 loss to Hong Kong in the first round. He defeated
Justin Pipe in the first round of the
2015 World Matchplay, 10–7, before losing to
Michael van Gerwen 13–2 in the second round. He threw the first
nine-dart finish of his PDC career at
Players Championship 17. At the
World Grand Prix, Lewis survived two match darts from
William O'Connor to edge past him 2–1 in the first round and then came from 2–0 down in sets against
Michael Smith to win 3–2. In his first major event quarter-final he was whitewashed by Van Gerwen 3–0.
Robert Thornton missed one match dart in the first round of the
Players Championship Finals to allow Lewis to win 6–5. He led
Dave Chisnall 8–6 in the second round, but lost four legs on the spin, missing three darts to force a deciding leg.
2016 Lewis lost 3–1 to
Daryl Gurney in the first round of the
2016 World Championship. In the second
UK Open Qualifier, Lewis reached the semi-finals and was narrowly beaten 6–5 by
Alan Norris. This gave him entry in to the third round of the
main event and
Stephen Bunting hit legs of 12 and 11 darts to move from 8–7 down to win 9–8. In the penultimate
Players Championship event, Lewis eliminated the likes of
Benito van de Pas and
Robert Thornton to play in the quarter-finals, where he lost 6–5 to
Simon Whitlock. He recorded a 6–4 win over
Jamie Caven in the opening round of the
Players Championship Finals, before being knocked out 6–4 by
Dave Chisnall.
2017 Lewis won a match at the
World Championship at the fifth time of asking when he edged past
Mick McGowan 3–2. He was knocked out by
Peter Wright in the second round with a score of 4–0.
2018 Lewis failed to qualify for the
2018 PDC World Darts Championship via the Order of Merit, saying on
Twitter that he was really disappointed in himself for his failure to qualify. However, he finished third at the PDPA Qualifier in
Milton Keynes, winning a place in the preliminary round. After defeating
Kenny Neyens in the preliminary round, and compatriot
Jonny Clayton in the first round, he defeated world number two
Peter Wright in the second round, before knocking out
James Richardson to reach the quarter final. In the quarter-final, Lewis
whitewashed
Darren Webster. In defeating Richardson and Webster, he became the first player to qualify for a quarter-final, and subsequently a semi-final, after starting in the preliminary round. Lewis then defeated
Stephen Bunting 6–2,
Danny Noppert 6–1, and
Joe Cullen 6–3, before losing to
Gary Anderson 6–3 in the semi-finals.
2019 Lewis qualified for the
2019 PDC World Darts Championship through being in the Top 32 on the Order of Merit. He entered the tournament in the second round as he was seeded 28th. There he faced
Cody Harris, against whom he was leading 2–0, but the match went into the deciding set after a comeback from Harris. In the deciding set, Lewis whitewashed Harris and advanced into the third round. He faced the fifth seed,
Daryl Gurney, and again Lewis led 3–1 in sets, but yet again the match went to a deciding set. Lewis won the match 4–3, winning the final set and reached the last 16 of the
PDC World Darts Championship for the second year in a row. In the fourth round he was
whitewashed by
Dave Chisnall 4–0 in sets. At the
2019 UK Open Lewis was seeded into the fourth round, where he defeated
Adrian Lewis 10–9 in a deciding leg. In the fifth round Lewis lost to
Josh Payne 10–7. Lewis did not qualify for any other major tournaments or European Tour events during the rest of the 2019 season. In Players Championship tournaments he was able to win just £7,000 during the whole year and ended up ranked 105th on the Players Championship Order of Merit.
2020 Close to the cut-off for
2020 PDC World Darts Championship he slipped out of top 32 and subsequently did not qualify for the event. He was not able to defend the prize money from the semifinal two years ago and slipped down to 57th place in PDC Order of Merit. It was still enough to maintain his Tour card. Lewis was seeded into the third round of
2020 UK Open and defeated
Ross Smith 6–5 in a deciding leg. In the fourth round he lost to
Mensur Suljović 10–4. Although the season was influenced by the outbreak of COVID-19, Lewis again struggled and did not qualify for any other major tournament. He qualified for the
2020 International Darts Open, but lost to
Robert Marijanovic 6–0 in the first round, scoring a three dart average of only 57.72. In September, Lewis announced that he was stepping away from the darts to focus on his private life. It was not disclosed at the time whether or not he intended to surrender his PDC Tour Card. In October, after losing in the European Tour event, Lewis revealed that he was suffering with anxiety disorder. Despite this statement, he entered the
PDC World Championship PDPA UK Qualifier. Lewis was the fifth seed for the qualifier and defeated
David Pallett and
Alan Tabern 6–2 to reach his quarter's final. Lewis defeated
Robert Thornton 7–5, to qualify for the
2021 World Championship.
2021 At the
PDC World Championship Lewis played ProTour qualifier
Luke Woodhouse in the first round and came back from 2–0 down to win 3–2 in sets. In the second round he won the opening set and the fourth set against the eventual champion
Gerwyn Price, but lost 3–2. ==World Championship results==