Simon Yates will go into the final five days of the Giro d'Italia as clear favourite after surviving Tuesday's time trial with a 56-second lead.
On a day when Australia's Rohan Dennis took the stage win, Yates finished the 34.2km course in 22nd place.
That was 97 seconds down on Dennis, but more importantly only 75 off reigning champion Tom Dumoulin in third.
Yates, who began Tuesday 2mins 11secs ahead of Dumoulin, said: "I'm very satisfied with where I stand now."
He added: "I'm really happy. I felt good in the first half. I had a good rhythm. I was trying to hold on to my position, but I died in the final 10km.
"Being in the lead after the time trial changes my tactics for the remaining stages. Unfortunately for the fans, I might be more defensive."
Dumoulin was 21 seconds up on Yates at the first time-check, 12km in, and had extended that to 48 seconds at 24km.
The world time-trial champion had won the Giro a year ago in large part through his dominant form against the clock and would have hoped to take much more out of Yates, who has struggled in time trials in the past.
But Yates had come home seventh in the short opening time trial on the first day of this Giro in Jerusalem and his hard work over the winter on his aero position paid off when he needed it most.
There was a solid ride from Chris Froome, the Briton 35 seconds down on stage winner Dennis to move back up to fourth on the general classification, 3mins 50secs behind Yates.
Italy's Domenico Pozzovivo is in third, with France's Thibaut Pinot the big loser after a disastrous performance saw him cross the line over three minutes behind Dennis' time.
But it was Yates' day, the 25-year-old having only one worrying moment when he took the wrong line through a late corner, losing a few seconds but no more.
No Briton has ever won the Giro and with three mountain stages to come on Thursday, Friday and Saturday before the race finishes in Rome on Sunday, there is still scope for his rivals to attack - and terrain to test his nerve.
But the rider from Bury, near Manchester, has been in peerless form in the mountains across the first two and a half weeks and will know he has history in his sights.
Stage 16 results:
1. Rohan Dennis (Aus/BMC Racing Team) 40mins 00secs
2. Tony Martin (Ger/Katusha-Alpecin) +14secs
3. Tom Dumoulin (Ned/Team Sunweb) +22secs
4. Jos van Emden (Ned/LottoNL-Jumbo) +27secs
5. Chris Froome (GB/Team Sky) +35secs
6. Fabio Aru (Ita/UAE Team Emirates) +37secs
7. Alex Dowsett (GB/Katusha-Alpecin) +40secs
8. Diego Ulissi (Ita/UAE Team Emirates) Same time
9. Chad Haga (USA/Team Sunweb) + 47secs
10. David De La Cruz (Spa/Team Sky) at 1min 01secs
22. Simon Yates (GB/Mitchelton-Scott) at 1min 37secs
1. Simon Yates (GB/Mitchelton-Scott) 66hrs 39mins 14secs
2. Tom Dumoulin (Ned/Team Sunweb) +56secs
3. Domenico Pozzovivo (Ita/Bahrain-Merida) +3mins 11secs
4. Chris Froome (GB/Team Sky) +3mins 50secs
5. Thibaut Pinot (Fra/Groupama-FDJ) +4mins 19secs
6. Rohan Dennis (Aus/BMC Racing Team) +5mins 04secs
7. Miguel Angel Lopez (Col/Astana Pro Team) +5mins 37secs
8. Pello Bilbao (Spa/Astana Pro Team) +6mins 02secs
9. Richard Carapaz (Ecu/Movistar Team) +6mins 07secs
10. George Bennett (NZ/LottoNL-Jumbo) +7mins 01secs