Bottas put in the fastest time of 1m20.325s just before 1pm local time on soft tyres, going 0.055 seconds faster than Vandoorne managed on the new hypersoft compound.
Hamilton was scheduled to take over from Valtteri Bottas mid-day, but given the delay in Mercedes' programme, the four-time world champion opted not to run to save his team the time necessary to organize a driver change.
"With the weather conditions being up and down and the loss of track time we had yesterday (Monday), it made sense to keep Valtteri in the vehicle this afternoon", said Hamilton.
"If I perform on the level I am aiming for at every single race, I hope that will do the job, but I am not going to start wasting my energy on mind games". "It is handling good so far. I don't know about performance, but with the general operation everything is really smooth".
"For me, if I perform at the level that I aim to perform, I hope to see more on-track battles with Lewis". The auto spent most of the afternoon in the garage after the engine cover showed tell-tale signs of overheating around the exhaust. McLaren had a better morning than on Monday, when Fernando Alonso's vehicle lost a wheel and crashed into the gravel, with Belgian Stoffel Vandoorne third fastest but with only 37 laps to his name.
Hamilton is understood to still be at the circuit, and the team claim he was willing to go along with their decision to give Bottas an entire day behind the wheel.
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That came seven days after she won the super-G by.01 seconds and shocked everyone, including herself. When reporters grew curious, she explained that winning a gold medal had caught her off-guard.
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After starting from the tenth, Lahiri was two-under through 13 holes before he dropped the bogeys on fifth, seventh and eighth. Lovemark followed an opening-round 68 with a 69 on Friday to climb into a tie with List at 3-under for the tournament.
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By going after Putin's wealth, which undoubtedly is squirreled away in banks around the world, including the USA and Switzerland. By contrast, Clinton, former USA secretary of state, was blistering in her condemnation of the Russian dictator and his henchmen.
'The miles in these conditions are less valuable than proper miles in proper conditions, but I will take it, ' Bottas said. I think the auto is working, we didn't have any problems reliability-wise.
Of course, it is well known that Hamilton is no fan of testing, especially when the weather compromises running.
The opening winter test concludes on Thursday with four further days of practice next week before the new season gets under way in Australia.
Fernando Alonso was the first driver to emerge from his garage as he completed one lap in his McLaren before returning to the pits.