Red Bull were quickest in final practice for the Korean Grand Prix
Vettel leads Webber with Rosberg and Hamilton third and fourth for Mercedes
By Mike Wise in Yeongam
Last Updated: 05/10/13 7:43am
The defending World Champion lapped the 5.615km Korea International Circuit in a time of 1:37.881s to go 0.137s faster than Webber, who carries the ten-place grid penalty he picked up in Singapore into Saturday afternoon's qualifying session.
Mercedes were next up, with Nico Rosberg heading Lewis Hamilton. The latter had described his performance on Friday, when he was fastest in both sessions, as his best for some time but was almost half a second down on Vettel in P3.
Even so, Hamilton appeared to struggle with traffic during the closing moments when drivers undertook their qualifying practice runs.
Ferrari's Fernando Alonso was fifth, two places ahead of team-mate Felipe Massa. Sandwiched between them was the Lotus of Romain Grosjean, whose own run on supersoft tyres was compromised when he got out of shape in Turns 15 and 16.
Team-mate Kimi Raikkonen was eighth, with Sauber's Nico Hulkenberg an encouraging ninth ahead of Jenson Button's McLaren. His team-mate Sergio Perez was 14th, two places ahead of Force India's Paul di Resta, who has admitted struggling for single-lap pace so far this weekend.
There were few surprises throughout the order, with Max Chilton 22nd fastest about 0.6s slower than team-mate Jules Bianchi. The question now is whether Mercedes, whose qualifying performances have been more muted of late, can cause a surprise later.
With downforce to spare, Red Bull have been running less rear wing in the first sector, which features one of the longest straights on the calendar. Webber (317.7km/h) was right up there when measured through the speedtrap - suggesting that the Australian is targeting the first DRS zone as the place to make up ground in Sunday's race.
Each sector is markedly different - the lap tightens as it progresses - yet the World Champions finished the session fastest in all three. Can either Hamilton or Rosberg challenge? Qualifying starts at 6am BST.