Bottas out qualified Hamilton on Saturday but was behind both the Ferrari's as Vettel and Kimi Raikkonen secured the first front row lockout for the Scuderia since the 2008 French GP.
Ricciardo and Verstappen, the latter a sensational maiden victor in Barcelona past year, might have to wait a little longer to make a lunge at the race lead, however, with engine supplier Renault delaying its latest power unit specification until July due to reliability concerns.
"There are two top teams fighting for both championships and I expect Red Bull will also eventually join the club", Mercedes boss Toto Wolff said.
However the leader managed to get DRS himself as traffic within one second allowed him to use the system and hold off the advancing prancing horse.
Hamilton's Mercedes team and Ferrari, spearheaded by four-time champion Vettel, arrived in Spain for the start of Formula One's European season with two victories each under their belt.
Massa, who ended up supporting Kimi Raikkonen's championship bid when they were team-mates at Ferrari in 2007, is sure Bottas is capable of matching Hamilton after his Russian Grand Prix win.
The Red Bulls of Max Verstappen and Daniel Ricciardo were fifth and sixth fastest, with Verstappen 0.106s off Vettel.
It is too early to make any conclusions about relative pace, not least because Vettel's session was disrupted by a gearbox problem on the pit straight.
"It's definitely a step forward", he said of Mercedes' W08 upgrades.
"I didn't get everything together, I wasn't too happy but I can feel the auto is quick so that is good".
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Hamilton added to his reputation as one of the most eccentric characters of F1 by bringing Roscoe, one of his two bulldogs, to the packed pre-race news conference on Thursday. "It was OK but as I said, we can improve".
"This inter-team battle is a totally different situation that what we have seen over the last three years", Wolff said.
Nico Rosberg, victor of the first four races in 2016, won the title last season with Mercedes, while Hamilton won the previous two championships.
"I feel happier than I did this morning but we still need to work very hard to get more pace in the vehicle and also the engine".
Hamilton won here 2014, but his first-lap collision with Rosberg a year ago knocked both out of the race and marked a low point in their contentious partnership.
"As always we will work hard to find any performance".
Like Toro Rosso last year, Sauber have elected to run a year-old Ferrari power unit for this season, which is going to hamper their development.
At the back of the field, it was a dismal day for home hero Fernando Alonso.
"Of course Bottas is a credible competitor", the three-times world champion said when asked if he believed the Finn was in the running for the title.
He hadn't contended since then, but has a chance this season in this new and unpredictable F1.