Chris Froome falls then falters in a tough start to his Giro D'Italia challenge

Team Sky star Chris Froome's attempt to win a third straight grand tour got off to a nightmare start at the Giro d'Italia on Friday.

The four-time Tour de France champion's bad day at the office began when he crashed heavily on his right side during a reconnaissance ride of the 9.7-kilometre course, a twisting and undulating route around Jerusalem's city centre.

His team said it was just a case of cuts and bruises but that looked like an understatement four hours later when he went through the intermediate split way down on the early leader Rohan Dennis.

That impression was rammed home less than four minutes later when the last man on the course, defending champion Tom Dumoulin, went through the finish line in a blistering time of 12 minutes two seconds - two seconds quicker than Dennis and a massive 37 seconds better than Froome, whose time was good enough only for 21st on the day.

Australia's Dennis, a specialist over short distances, had sat in the so-called hot seat as the man to beat for over two hours but none was hotter than Dutchman Dumoulin.

The world time-trial champion now knows he should be able to put serious amounts of time into all his rivals for the general classification in the Giro's second time-trial, a longer, flatter effort at the start of the third week on May 22.

Froome, however, will be desperate to wrest back control of this race by then and he will get chances to do so, with five of the Giro's eight mountain-top finishes coming before that 16th stage, but he will need to show much better form than he displayed here.

The fact he lost nearly all of his deficit to Dumoulin in the more technical first half of the course suggests he was struggling to accelerate out of corners and he also appeared to be cornering very conservatively - both understandable results of a painful tumble.

Losing to Dumoulin and Dennis on this course is no major embarrassment but the fact he is also behind Italy's Domenico Pozzovivo and Frenchman Thibaut Pinot, two challengers for victory in Rome in three weeks' time and neither known for their time-trialling, will smart.

And the fact that a trio of climbers - New Zealand's George Bennett, Italian Fabio Aru and Colombian Miguel Angel Lopez - who also crashed whilst checking the course, are only just behind would not have been part of the plan.

But if Froome's flop was a blow for British hopes, there was plenty to cheer elsewhere.

Alex Dowsett beat Sir Bradley Wiggins in a Giro time-trial in 2013 so his fifth-place finish in Jerusalem is perhaps not a huge surprise, although it is a timely return to form for the Essex-born rider who now races for Team Katusha.

Even more impressive, though, was the storming ride by Bury's Simon Yates, just four seconds behind Dowsett and 20 seconds off Dumoulin.

The Mitchelton-Scott man has already won two mountain stages this season and had come into this race telling people he was at a disadvantage in the time-trials. If he was bluffing, he will not get away with it again.

The third fastest man on a warm and sticky day was Belgium's Victor Campenaerts, only a fraction of a second slower than Dennis, with Portugal's Jose Goncalves fourth, 12 seconds back.

Further down the field, but probably not too upset, were Irish duo Nicolas Roche and Sam Bennett - 74 and 79 seconds slower than Dumoulin, respectively - and the fourth British rider in the field, Hugh Carthy, who recorded the same time as Bennett.

For the latter, this time-trial was more of a warm-up for Saturday's 167-kilometres ride up the Mediterranean coast from Haifa to Tel Aviv, where a bunch sprint is practically guaranteed to erupt by the seaside.

For Froome, it should be an opportunity to recover and regroup. With so much talk about his adverse test for an asthma drug at last year's Vuelta and whether he should even be here, the start of the race was meant to bring some respite.

There is a long, long way to go in this story but the first chapter has gone much the same way as the preface - lots of questions and most of them about him.