Brian Davis and Alastair Forsyth share third place at Valderrama Golf Club.
This event is reserved for the top-60 on the European Tour Order of Merit, but several players, including top money leaders Ernie Els and Retief Goosen, along with world No. 1 Vijay Singh, elected to skip the event.
Garcia did not look like he would be near the top of the leaderboard on Thursday when he bogeyed the third hole. He rebounded with a birdie at the next, then birdied the sixth and eighth holes to make the turn at 2-under-par 33.
At the par-5 11th, Garcia collected his fourth birdie of the round to reach 3 under par for the championship. The Spaniard birdied No. 16 to join Lara in the lead.
Garcia, ranked 10th in the world, had good chances to take sole possession of first on the final two holes at Valderrama. He missed a 9-foot birdie try at the 17th, then missed a 7-footer to go to minus-5 at the closing hole, but Garcia was happy with his round in windy, difficult conditions.
'I really enjoy it when a course is tough,' said Garcia, who won his last start at the Mallorca Classic. 'There are some places where if you don't make every putt you don't have a chance of winning. Here, you don't need to make everything, shoot even or 1 under and you're still in the tournament.'
Lara mixed a birdie at the second with a bogey at No. 4, then suffered a bee sting on the foot at the fifth hole.
'I have a bad cold and then the bee stung me, so maybe I played with less pressure because my mind was on other things,' admitted Lara, who bogeyed No. 7 to fall to 1 over par.
Things changed for Lara at the ninth. He birdied the hole, then tallied back-to-back birdies at 11 and 12 to reach 2 under for the tournament. Lara birdied the 15th, then finished his round in interesting style.
He sank a 15-foot birdie putt at the 16th, but missed the green with his third shot at Valderrama's famous, par-5 17th. Lara duffed a chip with his fourth, but chipped in for par. He parred No. 18 to post the clubhouse low in better conditions than Garcia.
'The sting bothered me for about four holes then I started to birdie holes and didn't even remember it,' said Lara. 'The important thing is that I took advantage of the birdie chances. I felt very comfortable but you can't ever say you are in control, because if the wind blows, it's very complicated.'
Lara is winless on the European Tour, although he tied for third earlier in the year at the Qatar Masters. He played in the final group Sunday with eventual champion Goosen at the European Open in Ireland, but the 27-year-old believes he's headed in the right direction.
'I played well in Ireland,' said Lara, who tied for fifth at the European Open. 'I am giving myself more options. I finished third in Qatar, so I am getting closer and closer.'
Luke Donald, a European Ryder Cupper and two-time winner this season, posted a 2-under-par 69 and is tied for fifth place with Christian Cevaer, Peter O'Malley and Jonathan Lomas.
Bradley Dredge, Marcus Fraser, Peter Hanson and Trevor Immelman are the only other players under par through the first round. They carded rounds of 1-under-par 70.