Zverev won 6-3, 4-6, 6-2 over Czech Vit Kopriva and will face fellow German Yannick Hanfmann in the next round of the traditional Wimbledon warm-up tournament.
The 29-year-old broke through for the first Grand Slam victory of his career with a dramatic five-set win over Italy's Flavio Cobolli at Roland Garros earlier in June.
It was Zverev's fourth Grand Slam final and second on the Roland Garros clay after some heartbreaking near misses in his career.
"The first matches after a surface change are always tricky, but I'm happy that I took my chances," Zverev said on court after Tuesday's win.
Cobolli's first-round defeat by American Frances Tiafoe on Monday in Halle snuffed out the chance of a rematch of the Roland Garros final.
Zverev has twice made the final at the Halle Open, but has never won the tournament. Wimbledon begins on June 29th.
A finalist at the Australian and US Opens, Zverev has not made it past the fourth round on the Wimbledon grass.