Red Bull led the opening practice session for the Azerbaijan Grand Prix after making the best use of the softest compound tyre to beat Ferrari and Mercedes to the top spot. Then suddenly I lost the rear and I had like a four-wheel power slide into the barrier.
"It was very weird", Verstappen told Sky Sports. "I could see I wasn't going to make the corner so chose to take the run off, as I turned right I lost the rear", Verstappen said. Perez, unhurt in his late off, took fourth place ahead of the Mercedes of Lewis Hamilton and Valtteri Bottas. He finished the second session in 10th. Vettel, meanwhile, went off at Turn 8.
Alonso, who along with team-mate Stoffel Vandoorne has a 15-place grid drop due to new engine components, suffered the failure through Turn 13, with smoke trickling from the rear of the MCL32.
McLaren is the only team yet to score a point, and continues to be blighted by its unreliable Honda engine, prompting growing speculation that management is out of patience and considering a deal with Mercedes as its engine supplier.
So now the order was Verstappen, Ricciardo, Perez, Bottas, Ocon and Hamilton.
That came just before Perez brought out the red flags with just under 20 minutes of the session remaining, wrecking the right hand side of his Force India at the ultra-tight castle section after having several bites of turning into the auto, and most likely jeopardizing his running in a few hours' time.
The first practice got underway under a clear sky with track temperatures at a blistering 54 degrees C (129 degrees F).
Brazilian Felipe Massa of Williams also topped the time sheets at one point, as the lap timings tumbled and most drivers endured spins and "moments" on the slippery and tricky track that takes in part of the ancient city of Baku.
However, the Briton's time was set on the soft tyre as his running was disrupted by Jolyon Palmer crashing into the barriers at the castle chicane which brought out a red flag. With F1's fastest top speed, and its combination of long straights and hard-braking corners, it poses big problems for grip.
The marshals took just over 10 minutes to clear the vehicle and debris, allowing the session to get restarted with just under six minutes to go.
Perez's crash resulted in the session being delayed for more than 10 minutes as the circuit's marshals removed his stricken vehicle and cleared the track of debris.
While nearly every driver could recall a moment they had to take to the run-off area, Romain Grosjean was the main culprit as he complained of brake problems that saw the Haas driver take to the escape road time and again.