Third fastest time in the Volta ao Algarve time trial was enough for Geraint Thomas to maintain his impressive 30-second lead.

The Welshman powered through the 19-kilometre test in a time of 21 minutes and 54 seconds to put up a stern defence of his yellow jersey in Sagres.

Fastest through the opening split, Thomas was the final rider across the line and stopped the clock just three seconds shy of stage winner Tony Martin (Etixx – Quick-Step).

With two stages to go Thomas retained his overnight advantage to the second, while top 20 performances from Ben Swift (15th), Salvatore Puccio (18th) and Richie Porte (19th) topped off a good day for Team Sky.

Porte debuted the green and gold of his Australian national champion’s skinsuit and elevated himself to ninth overall, 1:33 back on Thomas heading into the Malhao stage he won in 2012.

On a rolling course from Vila do Bispo to Sagres it was Anton Vorobyev (Katusha) who set the early benchmark with a 22:10. That time stood up for much of the day before Adriano Malori (Movistar) stuck in a 21:51.

Martin snuck ahead by a matter of tenths to win the stage, with the biggest smile reserved for Thomas who now gets set to defend the lead into the weekend. Another classification jersey belongs to Sebastian Henao after the Colombian retained the white young rider's jersey with another impressive ride.

After the stage Sports Director Gabriel Rasch talked about the time trial and looked ahead to a potentially decisive test on Saturday.

“G pulled out a great ride today," he confirmed. "He started off really fast and he had a lead over Martin at the first split, but the last part was really hard and he just lost out by three seconds at the end. It was really close though.

“Richie said he didn’t have the best day and obviously he was pretty disappointed. He really really wanted to produce a ride but sometimes it doesn’t happen.

“Tomorrow it’s a big day and we’ll put everyone behind G. It’s a climb we know well and we’ll give it everything to keep him in the jersey.”