Leclerc, winner of the previous round in Italy and on pole for the past three years in Baku, bounced back with a late lap of one minute 43.484 seconds to lead second practice after missing half of the first session when he hit the wall.
Red Bull's Sergio Perez, a two-time winner in Baku and the driver with the best record around the city circuit was a mere 0.006 slower.
"The pace was there today, but between the incident in FP1 (first practice) and a problem we had in FP2 with the steering, we didn’t complete too many laps," said Leclerc.
"It will be important for us to have a smooth FP3 (final practice) and get ready to extract the most out of qualifying tomorrow."
Perez's teammate and Formula One leader Max Verstappen had been fastest in the three-times halted first practice session with a lap of 1:45.546 on the chequered flag, but dropped to sixth in the later one and complained of understeer.
"We learnt quite a bit and now it's just about tidying up the things that we tried, but I think so far we have been more competitive this weekend so that’s positive," said Verstappen, who has a 62-point lead over McLaren's Lando Norris.
Norris was fourth fastest in practice one and 17th in the second after looking quick but was then blocked by Alpine's Pierre Gasly.
"We’re quite a long way off," the Briton told F1 TV. "I’m having to push way too much to try and get a lap time out of it. I think we have quite a lot to find, honestly.
"Compared to Mercedes, Ferrari and Red Bull, they’re all very similar and then there’s a good three, four tenths (of a second) gap back to us. So a lot of work for us to do."
Hamilton Happy
Seven-time world champion Lewis Hamilton ended the day third fastest for Mercedes, 0.066 off the pace, after setting the second-best time in opening practice.
Red flags were waved in practice one - first for a marshal to collect debris and then after separate crashes involving Leclerc and Williams' Argentine rookie Franco Colapinto.
Leclerc went into the wall at turn 15 with 33 minutes remaining, the Monegasque taking too much speed into the corner and locking up.
"I took the dirt on the outside," the Italian Grand Prix winner said over the team radio, with other teams also complaining that the temporary street circuit was dirty with low grip.
Colapinto also hit the barriers, at turn four with 18 minutes to go, with the back end snapping around and smacking the wall.
The Argentine was starting his second race weekend after replacing dropped American Logan Sargeant until the end of the season.
That session resumed with 11 minutes remaining and ended with Verstappen fastest at the finish as the team's floor upgrade appeared to be paying off as Red Bull sought to recover their early season form.
British teenager Oliver Bearman made his Haas debut as a replacement for suspended Kevin Magnussen, lapping 11th fastest and 0.162 quicker than teammate Nico Hulkenberg in practice one.
Bearman was 10th in the second session, with Hulkenberg eighth.
Alpine's Esteban Ocon reported a loss of power early on, with his first session ending early. The Frenchman was 19th in the later stint.
