Tagliani, a Montreal native racing on his home track, drove the No. 2 Soloson Ford/Riley to a best lap of 104.284 mph (1 minute, 33.518 seconds) on the 2.709-mile, 15-turn road course late in the second of two Thursday practice sessions.
"Now I can get a good night's sleep," Tagliani said. "I was a little nervous coming to a championship-contending team and not being competitive. Today was the first time I drove a DP. I didn't even have a seat fitting. This is an amazing learning curve. I just wanted to do good job."
Tagliani's lap in the second practice session of the day backed up the lap Ryan Dalziel turned to lead the opening two-hour session practice earlier Thursday afternoon. Dalziel and Tagliani will share co-driving duties in the No. 8 Starworks Motorsport Ford/Riley, while Tagliani will also share the No. 2 machine with Alex Popow in Saturday's two-hour event.
Alex Gurney, in the No. 99 GAINSCO/Bob Stallings Racing Corvette DP, led the combined practice for much of the final session, but settled for second at 104.057 mph after Tagliani's chart-topping lap.
Gurney, a three-time pole winner this season who will share driving duties with Jon Fogarty, scored his most recent victory in the series on the Gilles Villeneuve track last season. His most recent GRAND-AM pole position was two races ago at Indianapolis.
Leh Keen was fastest for the day in the GT class, logging a lap at 97.280 mph (1 minute, 40.251 seconds) in the second session in the No. 59 The Brumos Companies Porsche GT3 he shares with Andrew Davis. That lap edged out the No. 57 Stevenson Auto Group Camaro GT.R driven by John Edwards, who was second on the combined practice report at 97.092 mph. Edwards’ co-driver is Robin Liddell, who scored the GT victory in Montreal last year.
Qualifying for the Montreal 200, the 11th round of the season for the GRAND-AM series, is scheduled for 4 p.m. ET Friday. Saturday's two-hour race will take the green flag at 11:15 a.m. ET.