The win somewhat alleviated the frustrations of No. 2 Johnny Arcilla who failed to recover from a stiffening left leg and absorbed a 6-4, 3-6, 7-6 (9-7), 4-6, 6-4 decision from Woon-Sun Jun.
The two squads break their 1-1 deadlock today when the pivotal doubles is played at 1 p.m. with Joseph Victorino and Rolando Ruel Jr. being nominated by non-playing captain Johnny Jose to play against Hee-Seok Chung and Dong-Hyung Kim.
The actual protagonists, however, will not be known until noon today as the two teams could still change their line-ups.
The reverse singles will be played tomorrow starting at 10 a.m. with Tierro facing Jun in the first match and Arcilla battling Suk.
"Grabe ang pressure. Parang nagmadali ako sa opening set kaya natagalan akong maka-groove sa game,"admitted Tierro, now the countrys No. 1 mens campaigner who was only in his second Davis Cup match.
"I told you earlier we could spring some surprises here," exclaimed RP team manager Jean Henri Lhuillier, whose vision and support to the sport has tremendously contributed to the steady rise of the teams level of play.
For a while, the skeptics seemed to have the upperhand when Tierro lost a 3-2 lead in the first set to fall back, 4-5. But big serves and the Koreans double faults gave him the next three games and the first set.
It was the same in the second set as Tierro wasted a 5-4 lead and a setpoint before breaking the Korean in the 12th game for a 2-0 advantage.
The Korean took a 2-4 lead in the third set as Tierros left leg started to stiffen everytime he served. A quick stretching exercise marked the pain and Tierro took the next four games to give the Philippines a 1-0 edge in the best-of-five matches tie.
In the case of Arcilla, the former Filipino No. 1 banked on his experience to keep going against the hard-serving world No. 713 Jun, who was playing in his first Davis Cup match.
But as fate would have it, Arcillas left leg gave way for the Korean to gain confidence and whack winners after winners in the fifth and final set.
"Your player is a good one. Jun has no experience and used only his power. If he (Arcilla) was not injured, he could have won the second match easily," South Korean non-playing captain Gap-Taik Ro said.