More than 15,000 fans turned out in pouring rain at the Mugello circuit in Italy on Tuesday to see Ferrari's Fernando Alonso lap fastest in Formula One's first mid-season test since 2008.   The Spaniard, who clocked a best time of one minute 12.444 seconds at the Ferrari-owned track north of Florence, felt for the crowd on an afternoon red-flagged briefly due to a thunderstorm. "It's a shame about the rain, which complicated the running of this first day of testing, and a shame for the spectators who deserved to see more of a show," said the double world champion. The test is a key one for his Italian team, desperate to sort out a difficult car that has been off the pace despite Alonso's victory against the odds in a rain-soaked Malaysian Grand Prix in March. The rain prevented Ferrari and the 10 other teams present - all but Spanish stragglers HRT - from carrying out a full day's work, however, with only a small window of dry running in late morning. Some teams sat out the afternoon altogether to save tyres. Alonso, who hands over to Brazilian team mate Felipe Massa for Wednesday, did a total of 46 laps with the afternoon limited to practice starts. Lotus changed their plans, with Kimi Raikkonen no longer scheduled to take part in the test and French team mate Romain Grosjean now slotted in for two days instead of one after Belgian reserve Jerome D'Ambrosio opened the test. "We've opted for one driver for the next two days so we can make better use of the time after losing this afternoon's running," said the team's trackside operations director Alan Permane in a statement. Australian Mark Webber was second on the timesheets for champions Red Bull. "The weather wasn't great today so we didn't get to do much running in the dry. Really we only got one decent run on the slicks," said Webber who did just 24 laps. "Then it rained after lunch and with limited sets of wets available, you can't do that much. We're hoping for better over the next couple of days. It's an important test. "We have a lot of information to gather and, while today didn't quite work out as expected, I'm optimistic that over the course of the next few days we'll get the information we need." The Mugello test is the fourth and final one of the season for regular race drivers, with only a young driver test scheduled between now and the end of the year. Regular in-season testing is otherwise banned.