Tampa Bay is the better team, but I'm not going to buck the hot Stars especially since the Lightning have a short turnaround after their Thursday overtime victory against the Islanders to clinch that series.
So instead of getting involved with a side, I'm going the total route where I see each team producing at least two goals apiece. 
I highly doubt backup Stars goalie Anton Khudobin can repeat the magic he did against the Golden Knights when he stopped 153 of 161 shots for a .950 save percentage. 
The Lightning have a more potent attack than Las Vegas and they have their top playoff scorer, Brayden Point, back in the lineup. There's even the outside chance Steven Stamkos could suit up. He has yet to play during the Stanley Cup. 
Tampa Bay is averaging 3.3 goals during the playoffs. This is in line with the regular season when the Lightning led the NHL in scoring at 3.5 goals per game. The Lightning has three attacking lines and scoring depth up and down their roster. 
Dallas has shown it can play and win with a wide open style. The Stars took out the Avalanche in that fashion. It wouldn't surprise me if the well-rested Stars came out super aggressive to take advantage of Tampa Bay's fatigue issue.