Lewis claimed his first ranking title in over three years as he powered to a Players Championship 20 title in Barnsley.
The 37-year-old defeated Boris Koltsov 8-4 in the final as he appears to be regaining form following a turbulent spell in the sport.
Since his last ProTour success in 2019, Lewis dropped out of the world's top 32 and has struggled to rediscover darts of old.
Nevertheless, the former world champion showed his class on Sunday with seven wins on the third day of action at the Barnsley Metrodome.
The victory not only earned Lewis £12,000, but it also secured his place in the World Matchplay.
The 2013 runner-up will make his 18th appearance at the event after missing the cut last year for the first time since his debut in 2004.
"I've worked hard for this, so I'm really happy," he said. "It's been amazing - I made a semi on the first day and that gave me the confidence to turn it on today.
"It's more important, because I thought I might not make the Matchplay - it was hard. After the first day when I got to the semis, it takes a bit of pressure off.
"I played alright yesterday and lost to Matt Campbell, and then today I thought 'right, come on, just give it what you've got'.
"I always believe in myself. If everything clicks, I've got a great chance - I can lose to anybody and I can beat anybody!"
Players Championship 20 results
Boris Koltsov 6-4 Krzysztof Kciuk
Martin Schindler 6-2 Steve Beaton
Adrian Lewis 6-4 Jonny Clayton
Nathan Aspinall 6-5 Jermaine Wattimena
Boris Koltsov 7-3 Martin Schindler
Adrian Lewis 7-2 Nathan Aspinall
Adrian Lewis 8-4 Boris Koltsov