Sebastian Vettel's morning benchmark time of 1m16.841s remained unchallenged in the afternoon session of the penultimate day of pre-season testing.
The Ferrari driver tacked on an additional 95 laps after lunch to set his lap count for the day at 144 laps/
AlphaTauri's Pierre Gasly put in a good effort in the closing stages of the session to conclude the day second overall, 0.225s adrift from Vettel, while Racing Point's Lance Stroll also relied on his morning performance to clock in 3rd overall.
The highlight of the session was the problem that befell Mercedes and Lewis Hamilton.
The six-time world champion was the last driver to take to the track in the afternoon segment as the Mercedes crews took their time to prepare the Briton's W11.
But 14 laps into his program, Hamilton suddenly stopped at the exit of Turn 5, the victim of an apparent engine issue.
The W11 was covered and loaded onto the flatbed and hauled back to its garage.
The Mercedes camp later announced that an oil pressure anomaly had automatically shut off Hamilton's power unit as a measure of precaution. However, the issue put a premature end to the team's running.
The complication was certainly a cause for concern for the Brackley squad whose customer, Williams, has suffered two engine disruptions since the start of pre-season testing.
While most teams extended their mileage in the afternoon, hot laps were few and far between has drivers focused on long runs and set-up work, meaning there was little change in the pecking order at the end of the day.