Guards Samantha Prahalis (11 points) and Ashlee Trebilcock (10) also scored in double figures for the Buckeyes (4-1), who bounced back from their first defeat of the season, an 87-80 overtime setback at Auburn on Sunday night.
Power forward Star Allen had a game-high 12 rebounds for the Buckeyes.
After the loss to the then-20th-ranked Tigers two nights previous, OSU head coach Jim Foster lamented his team's late defensive effort, but he had little to quibble with back home at Value City Arena on Tuesday night as the Buckeyes kept the clamps on Hartford from start to finish.
The Hawks (3-2) shot just 29.3 percent from the field (17 for 58) and committed 20 turnovers while getting credit for just nine assists.
"I thought we played very, very good defense," Foster said. "I think when you play good defense you have a chance to win a lot of games."
A desire for more defense led Foster to insert Trebilcock into the starting lineup for the first time this season, and she responded with two steals and five rebounds while making 4 of 5 shots from the field.
Known more for her shooting than her defense in the past, Trebilcock acknowledged that the message of "defense first" got through loud and clear.
"I think as a team we came out wanting to deny and be in help, especially after a loss," said the senior, who was a starter last season. "We came out extra pumped. We just wanted to get in their face and cause turnovers because that creates our offense."
Hartford (3-2) came in not just as the beast of the America East Conference, the Hawks also have a victory over then-No. 5 Duke on their resume this season.
MaryLynne Schaefer led the Hawks with 15 points, and Diana Delva had 10 rebounds.
"I thought they played excellent, took us out of everything we wanted to do, really disrupted our offense and I thought had a really balanced attack offensively," Hartford coach Jennifer Rizzoti said.
Ohio State took control in the first half with a 9-0 run that extended a six-point lead to 15.
Andrea Walker started the spurt with a layup at the 13:24 mark.
Lavender followed with an old-fashioned three-point play, Trebilcock maneuvered into the lane for a short jumper and Lavender made a layup to make it 24-9 with 11:50 to go.
Later the Hawks cut the lead to nine with an 8-2 run of their own, but the Buckeyes scored the last six of the half to push the lead to 38-23 when the horn sounded.
Lavender led all scorers in the first half with 12 points. She also grabbed a game-high seven rebounds and blocked two shots.
Trebilcock added seven for the Buckeyes. She also had two assists, a steal and two rebounds without a turnover in 16 minutes.
The Buckeyes shot 53.6 percent (15 for 28) in the first half, far outpacing the visitors, who made just 9 of 27 (33.3 percent).
Hartford committed 11 turnovers and had just four assists in the first half.