US Postal's Max van Heeswijk has won the first stage of the Tour of Murcia after a dramatic photo-finish.
Armstrong (right) was in contention throughout the stage
The Dutchman managed to pip German Erik Zabel and Spain's Ivan Gutierrez at the end of the gruelling 177km run.
Van Heeswijk's team-mate and five-time Tour de France champion Lance Armstrong finished in 57th place on the same time as the leaders.
Tour runner-up Jan Ullrich was 84th more than seven miniutes adrift after being dropped in the closing stages.
Armstrong will be looking to soar up the event rankings following Thursday's 21.3km time-trial.
US Postal's team director Johan Bruyneel was satisfied with Armstrong's performance.
"He is in good shape," said Bruyneel.
"Although the idea is to prepare here in Spain, not necessarily to win, we will all be racing at 100%, especially in the time trial on Thursday."
Armstrong stayed with the leading pack during the race and recorded a time of 4:20:51, the same as stage winner Van Heeswijk.
Ullrich, however, dropped off the pace with 25km to go and finished seven minutes and 35 seconds behind.
First stage results (177km Murcia to San Pedro del Pinatar)
1. Max van Heeswijk, Netherlands, U.S. Postal Service, 4
hours, 20 minutes, 51 seconds.
2. Jose Ivan Gutierrez, Spain, Illes Baleares-Banesto,
3. Eric Zabel, Germany, T Mobile, same time.
4. Jan Svorada, Czech Republic, Lampere, same time.
5. Isaac Galvez, Spain, Illes Baleares-Banesto, same time.
6. Alejandro Valverde, Spain, Com. Valencia-Kelme, same
7. Miguel Angel Perdiguero, Spain, Saunier Duval-Prodir,
8. David Navas, Spain, Illes Baleares-Banesto, same time.
9. Xavier Florencio, Spain, Relax-Bodysol, same time.
10. Ion del Rio, Spain, Costa Almeria-Paternina, same
57. Lance Armstrong, United States, U.S. Postal Service,
84. Jan Ullrich, Germany, Telekom, 7:35 behind.