Romain Grosjean put Lotus at the top of the timesheets on the opening morning of Formula 1's first pre-season test of 2013 at Jerez.
The Frenchman jumped to the top in the final minutes when he became the first driver to dip below the 1m20s barrier.
His fastest time, a 1m19.796s, put him comfortably clear of Force India's Paul di Resta and Toro Rosso's Daniel Ricciardo.
Di Resta, Force India's only confirmed driver so far for the forthcoming campaign, had himself jumped to the top of the timesheets moments before Grosjean's charge.
Ricciardo as a result found himself shunted from first to third in a matter of minutes. The Australian had set the pace for much of the morning running on Pirelli's new hard compound.
Half a second down the road was Mercedes's Nico Rosberg, whose morning was cut short by an electrical issue which forced him to stop at Turn 11, his car briefly smoking at the rear.
Rosberg had been the pacesetter until that point but was unable to return, ending the morning with just 11 laps under his belt.
That was still more than McLaren's Jenson Button, who suffered his own early maladies.
The Briton stopped out on track just three laps into his programme, bringing out the first red flag. A fuel pump-related issue then kept him sidelined for the rest of the morning.
There were no such complaints for Pastor Maldonado in the 2012-spec Williams FW34, as the Venezuelan completed 52 laps - the most of any driver - and ended the morning in fifth.
On his first day of testing as a Sauber driver Nico Hulkenberg finished seventh fastest, behind Ferrari's Felipe Massa, sixth in the F138.
Mark Webber got Red Bull's third consecutive title defence off to a low-key start as he came home eighth, more than three seconds slower than Grosjean's benchmark.
2013 F1 rookies Giedo van der Garde (Caterham) and Max Chilton (Marussia) rounded out the day's runners, just ahead of Button.
The pair were separated by just 0.182s, although both trailed the pace-setting E21 by more than five seconds.
Pos Driver Team Time Laps
1. Romain Grosjean Lotus 1m19.796s 24
2. Paul di Resta Force India 1m20.343s +0.547 40
3. Daniel Ricciardo Toro Rosso 1m20.401s +0.605 37
4. Nico Rosberg Mercedes 1m20.846s +1.050 11
5. Pastor Maldonado Williams 1m20.864s +1.068 52
6. Felipe Massa Ferrari 1m21.024s +1.228 47
7. Nico Hulkenberg Sauber 1m21.553s +1.757 32
8. Mark Webber Red Bull 1m22.959s +3.163 42
9. Giedo van der Garde Caterham 1m24.994s +5.198 21
10. Max Chilton Marussia 1m25.176s +5.380 21