TOUR DE FRANCE
Date: 4 July - 26 July
Coverage: BBC Sport website: text commentary of each stage and streamed BBC commentary of the last 90 minutes of each stage available; commentary on selected stages on BBC 5 Live sports extra
Astana enjoyed the stage win - but Cancellara stays in yellow
Lance Armstrong's Astana team narrowly failed to put the seven-time Tour de France winner back in the yellow jersey after a thrilling team time trial.
Astana won the 39km lap of Montpellier but ended two tenths of a second shy of wiping out Fabian Cancellara's lead and putting Armstrong top of the podium.
The Texan's outfit needed to beat Cancellara's Saxo Bank team by more than 40 seconds to put him in yellow.
Astana beat Garmin-Slipstream into second with Saxo Bank in third.
After four stages, Armstrong, 37, who retired after winning the last of his record seventh title in 2005, now has the same overall time as race leader Cancellara but is placed behind him after the results of Saturday's opener in Monaco were taken into account.
His Astana team-mate and 2007 champion Alberto Contador is third, 19 seconds back, and British duo Bradley Wiggins and David Millar are both in the top 10.
"We thought we had it," said Armstrong, whose team clocked 46 minutes and 29 seconds.
It was a strong performance from my team in the last kilometre. We can be proud that we defended this jersey and tomorrow again we will be in yellow
Tour leader Fabian Cancellara
"Based on the time splits on the course we thought we were close or thereabouts but, hey, that's cycling.
"We looked at our performance and we can say we did our best. We won the stage and gained time on our main rivals."
Armstrong moved up seven places from 10th to third after Monday's equally dramatic third stage, and showed that he intends to stay in contention for an eighth Tour crown, despite having several rivals in his own team which boasts pre-race favourite Contador as well as the impressive Levi Leipheimer.
The American would have become the oldest man to wear the yellow jersey if he had pipped Cancellara, but afterwards he suggested that he may not be able to keep up his challenge.
"I wanted to be one of the strongest in the race," he said. "I think that I am but I may not be the strongest to win. I think someone on this team will win.
"It's the Tour, I know the Tour and how to race it. Sometimes it pays to be old and experienced and not young and strong. We'll take it day by day.
"I don't think the jersey changes hands until Andorra."
Several teams suffered crashes because of the difficulty of the course, but seven Astana riders stayed together until near the end before five raced clear to beat the Garmin team of Millar and Wiggins by 18 seconds.
Astana's early pace had suggested they would be fast enough to put Armstrong in yellow but an earlier strong finish by his Swiss rival's Saxo Bank outfit proved crucial.
There was a dramatic wait when Astana finished before Tour officials confirmed Cancellara had kept the overall lead and afterward he laughed: "That is Swiss timing!
"I think we can be happy with today - it was a strong performance from my team in the last kilometre and we can be proud that we defended this jersey and tomorrow again we will be in yellow."
Italian outfit Liquigas came fourth, 58secs after Astana and one second ahead of Mark Cavendish's Columbia team.
But defending champion Carlos Sastre suffered his second big setback of the race, after losing time to key rivals in the opening stage time trial, when his Cervelo team finished eighth at 1:37 behind Astana. The Spaniard is now two minutes and 44 seconds off the lead.
Australia's Cadel Evans, the runner up in 2007 and 2008, also slipped further back and is now two minutes and 59 seconds behind Cancellara and Armstrong.
Denis Menchov, who like Sastre had a disastrous opening day, suffered again after crashing early in the course and is another 53 seconds further back.
Stage four result:
1. Astana 46 minutes 29 seconds
2. Garmin-Slipstream + 18 secs
3. Team Saxo Bank + 40 secs
4. Liquigas +58 secs
5. Team Columbia-High Road +59 secs
6. Team Katusha +1 min 23 secs
7. Caisse d'Epargne +1 min 29 secs
8. Cervelo Test Team +1 min 37 secs
9. AG2R La Mondiale +1 min 48 secs
10. Euskaltel-Euskadi +2 min 09 secs
1. Fabian Cancellara (Swi/Saxo Bank) 10 hours 38 minutes 07 seconds
2. Lance Armstrong (US/Astana) same time
3. Alberto Contador (Spa/Astana) +19 secs
4. Andreas Kloden (Ger/Astana) +23 secs
5. Levi Leipheimer (US/Astana) +31 secs
6. Bradley Wiggins (GB/Garmin) +38 secs
7. Haimar Zubeldia (Spa/Astana) +51 secs
8. Tony Martin (Ger/Team Columbia) +52 secs
9. David Zabriskie (US/Garmin) +1 min 06 secs
10. David Millar (GB/Garmin) +1 min 07 secs
30. Carlos Sastre (Spa/Cervelo) +2 min 44 secs
36. Cadel Evans (Aus/Silence) +2 min 59 secs
61. Mark Cavendish (GB/Team Columbia) +3 min 33 secs
161. Charlie Weglius (GB/Silence) +8 min 09 secs.