The 25-year-old, who before the match had earned just £50.74 in prize money in 2016, earned a 6-3 6-3 6-4 victory over Ricardas Berankis in the opening round on Monday.
It took just over two hours for Willis to reach the next round, and he had the perfect start by breaking his Lithuanian opponent's serve at the first time of asking.
Willis went on to save two break points and then broke serve again to take a one-set lead on the grass court at SW19.
The Brit battled hard to hold serve at the start of the second set, and he faced a test when Berankis, who is ranked 54th in the world, broke back instantly to keep him on Willis's shoulder.
The Slough-born player maintained composure, though, as he went another break up before wrapping up the second set, and with a home crowd behind him, he came through the third in 48 minutes.
Willis is expected to take home £50,000 in prize money from that first-round victory.