Add garlic, thyme, salt, pepper, olive oil, lemon zest, and lemon juice to a large Ziploc bag. Shake well to mix. Add chicken thighs.
Slice 1 lemon and add to the bag. Shake well to coat the chicken and marinate for 1 – 4 hours (longer is better).
Grill chicken skin side down for 3 – 4 minutes. Turn chicken skin side up and continue to cook, turning chicken occasionally, until done.
Slice the remaining 2 lemons.
Turn chicken skin side up and place the remaining lemon slices on top of the chicken. Cook for an additional 3 – 4 minutes. Remove chicken from the grill and let rest 5 minutes.
