- Sebastian Vettel edges Fernando Alonso in second free practice in Spain
- Vettel's Red Bull teammate Mark Webber third fastest in afternoon runs
- Vettel leading title race in bid for fourth straight championships
- Alonso fastest in wetter morning session at Circuit de Catalunya
Sebastian Vettel and home hero Fernando Alonso shared the honors in the opening practice sessions Friday for the Spanish Grand Prix Friday in Barcelona.
Vettel edged Ferrari's Alonso to claim his third straight Formula One crown last season and the pace of his Red Bull saw the German quickest in drying conditions in the afternoon session at the Catalunya circuit.
But Alonso, who had put on a show for his fanatical supporters to post the fastest time in the wet of the morning, was just 0.017 seconds slower than his arch rival in the second runs.
"The signs from today are very positive," he told the official F1 website.
Alonso is desperate to deliver a home win in Spain for the first time since 2006 but Vettel is a formidable obstacle off the back of his two victories already this season.
His Red Bull teammate Mark Webber was third fastest in second practice, with just 0.083 seconds separating the top three.
All the teams have come to Spain after a three-week break since Bahrain with upgrades to their cars and Vettel is cautiously optimistic his team will continue to set the pace.
"We have some new parts here but the days of big, big upgrades don't really happen now with the regulations how they are," he said.
"This afternoon was fairly conclusive, but this morning wasn't really much good with the weather.
"It's hard to say much about the harder tire, I think the number of pit stops will be the same here in this race as at the last few."
Finland's Kimi Raikkonen, the closest challenger to Vettel in this year's title race, was fourth fastest in his Lotus ahead of Brazilian Felipe Massa in the second Ferrari.
Britain's Lewis Hamilton spun his Mercedes early in the second session but claimed sixth fastest ahead of his teammate Nico Rosberg.
Two-time world champion Alonso braved the testing morning weather to clock the best lap of one minute 25.252 seconds with teammate Massa setting the second quickest time.
Saturday will see final qualifying for the fifth round of the F1 season, with grid position considered crucial on the Spanish circuit.