The reigning champion opened Friday's proceedings with a 6-3 6-4 quarter-final triumph over Jeremy Chardy at the ATP 250 grass-court event, setting up a last-four meeting with Sam Querrey.
And he was back on court less than five hours later in Eastbourne, just edging the opening set by breaking his American opponent's serve at 4-4.
The second was equally tight, but Lopez squandered two break points as the match headed to a tie-break.
Querrey found himself two breaks to one down in the decider, affording Lopez the chance to serve for the match, and he made no mistake in sealing a 6-4 7-6 (7-4) win.
Sandwiched between Lopez's two outings was the other semi-final between top seed Gasquet and Denis Istomin, eventually won by the Frenchman.
After seeing two early break points come and go, Gasquet left it late to move in front in the match, but was fairly comfortable in seeing out the 6-4 6-2 result.
"I played a good match," he said. "It was important to play well because Denis is dangerous.
"The key on grass is to serve and return well. I managed to do it.
"I'm very happy with the way I played, because it's always difficult to play on grass. You need to be strong on every point."