Ebihara, who won the Order of Merit money title on the European Senior Tour this year, birdied six of his first eight holes Wednesday at the Rolling Oaks course at World Woods Golf Club.
'I missed quite a few putts yesterday, and I practiced my putting after I played,' Ebihara said through an interpreter. 'I think the practice paid off today. Making those putts early really helped me the rest of the round. I'm in good position, but I know I can't relax. My goal is to play the last 36 holes in 5-under and see what happens.'
Smyth, who won the 2001 Madeira Island Open for his last win on the European Tour, posted a bogey-free round of 4-under 68, which featured four birdies in his first 10 holes.
Former major league pitcher and Celebrity Tour stalwart Rick Rhoden is part of a group in fourth place.
'I played much better and did a lot of good things,' said Rhoden, who shot a 4-under 68. 'I wasn't hitting the ball that well on the range. The ball was going left-to-right, which is not my normal shot. I just decided to go with it, and it worked today. All of my birdies were less than six feet, and I made quite a few easy pars.'
Mark Pfeil and Butch Sheehan, both of whom played significantly on the Champions Tour in 2002, share fourth with Rhoden at 6-under-par 138.
Rex Caldwell, Terry Mauney, Jim Ahern and Dave Barr are tied for seventh at minus-5.
David Eger, who shared the lead with Smyth after Tuesday's first round, struggled to a four-over 76 and is tied for 28th at 1-under-par 143.
The 36-hole cut fell at 4-over 148 and among the notable players to miss the cut were Bob Duval, father of PGA Tour star David Duval, and Jeff Thomas, who was one shot out of the lead after Tuesday's opening round but ballooned to an 81 Wednesday.
Full-field scores from the Champions Tour Q-School