The 2012 Special Election for the San Juan I Senate district, a contest between Representative Liza Fernández and ex-Municipal municipal worker and legislative aide Eddie Charbonier resulted in a comanding win for 4th District representative Liza Fernández
Following the resignation of Conservative Roberto Arango after nude pictures of him surfaced on the gay match app Grindr this seat presented a potent political test for both Santini and Schatz as both PNP leaders angled to run for the 2016 PNP Governor nomination.
Here, Santini desired a convention—dominated by the San Juan PNP he controlled—and Schatz (along with Guaynabo Mayor Héctor O'Neil) a special election, as each respective method would give them the best chance to win.
In this case, due to Schatz influence as a PNP Vice President a Special Election won out, allowing him & O'Neil an opening to challenge the Santini backed Liza Fernández with their own candidate, Eddie Charbonier
But, despite this being their best opening, the special election was still dominated by San Juan—and as Santini was powerful among the SJ PNP at the time—Fernández's was able to best Charbonier in a comanding victory.
I'll also note that on the same night, the primary was held for the general election in SJ-I, with redistricting Adding Aguas Buenas and removing a precinct in Guaynabo
here, the same dynamics showed up, except Santini had two endorsed candidates up for election (Liza Fernández and Zoé Laboy) to Schatz/O'Neil's Eddie Charbonier. This was the case as Schatz/O'Neil were focused mainly on getting charbonier elected to defeat Santini's main ally in the race
However in this, they failed, resulting in not just the aforeshown comanding victory in the special election—but a nearly identical victory in the Primary—with Zoé Laboy as the top vote getter—resulting in both Fernández and Laboy being nominated over Charbonier
With regards to the Proxy war, it was all for naught, with Thomas Rivera Schatz losing the senate in the PNP's worst statewide performance in 2012 and Santini losing reelection wholesale faced grave political wounds—Santina's mortal.
In doing so, making them a third rate contender, and not even a contender for the governorship in 2016 respectively.